GULICK  HYGIENE  SERIES 


PHYSIOLOGY;  HYGIENE 
AND  SANITATION 


I  BY  FRANCES  GULICK  JEWETT  | 


BIOLOGY 

LIBRARY 

G 


THE    GULICK   HYGIENE   SERIES 

EDITED  BY 

LUTHER  HALSEY  GULICK,  M.D. 


THE   GULICK  HYGIENE  SERIES 

PHYSIOLOGY,  HYGIENE 
AND  SANITATION 


BY 
FRANCES   GULICK  JEWETT 


GINN  AND  COMPANY 

BOSTON     •     NEW   YORK     •     CHICAGO     •     LONDON 
ATLANTA     •    DALLAS     •     COLUMBUS     •     SAN    FRANCISCO 


COPYRIGHT,  1916,  BY  FRANCES  GULICK   JEWETT 
ENTERED  AT  STATIONERS'  HALL 


BIOLOGY 

LIBRA 

916.3  G 


ALL   RIGHTS   RESERVED  LIBRARY 


GINN  AND  COMPANY  •  PRO- 
PRIETORS •  BOSTON  •  U.S.A. 


PREFACE 

It  is  the  purpose  of  this  volume  to  present  such 
material  on  physiology,  hygiene,  and  sanitation  as  may 
be  of  practical  service  to  young  people.  For  this  reason 
function  is  emphasized  rather  than  structure,  and  the 
laws  of  health  receive  more  attention  than  the  mechan- 
ical operation  of  bone,  muscle,  gland,  and  tissue. 

In  the  earlier  chapters  of  the  book  stress  of  teaching- 
is  laid  on  right  habits  of  sitting,  of  standing,  and  of  walk- 
ing; on  the  relation  of  the  school  desk  to  spinal  curva- 
ture; on  laws  of  growth  and  their  relation  to  correct 
habits  of  posture;  on  the  development  of  muscular  vigor; 
and  on  the  renewal  of  the  tissues  of  the  body. 

Attention  is  also  called  to  the  source  of  all  muscular 
energy  —  the  blood.  Simple  tests,  easily  applied,  explain 
the  cause  of  rapid  and  slow  heartbeat  and  show  how 
the  power  of  the  heart  and  of  the  lungs  may  be  increased 
gradually.  Reasons  are  given  why  the  untrained  heart 
should  not  be  greatly  taxed,  and  why  extreme  breath- 
lessness  is  objectionable.  The  effect  of  alcohol  on  the 
heart  and  on  the  arteries  is  made  plain,  and  the  effect 
of  tobacco  on  the  action  of  the  heart  is  illustrated  by 
means  of  the  sphygmograph. 

355256 


vi  PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Professor  Chittenden's  notable  experiments  with  sol- 
diers in  New  Haven  and  Dr.  Cannon's  experiments 
with  cats  in  the  Harvard  Medical  School  add  a  touch 
of  picturesque  reality  to  the  otherwise  prosaic  subject 
of  digestion.  Through  these  experiments  we  are  intro- 
duced to  the  change  of  food  from  solid  to  liquid  in  the 
alimentary  canal,  to  the  absorption  of  chyle  by  the  villi, 
to  the  enrichment  of  the  blood,  and  to  the  work  of  the 
liver  and  the  kidneys  in  purifying  the  blood. 

The  nervous  system  also  is  studied  primarily  from  the 
point  of  view  of  function  and  of  efficient  service.  The 
student  learns  how  the  body  is  controlled  by  laws  of 
habit  and  by  will  power,  how  habits  are  formed,  and 
how  it  comes  to  pass  that  a  happy  state  of  mind 
helps  on  the  cause  of  good  health.  . 

The  present  volume  is,  in  some  respects,  a  readjust- 
ment of  The  Body  and  its  Defenses.  Certain  subjects 
treated  there  have  been  pressed  into  smaller  compass 
here;  while  certain  other  subjects  touched  upon  there 
have  received  more  extended  treatment  here.  To  a 
large  extent  this  new  subject  matter  concerns  itself  with 
sanitation,  hygiene,  and  the  food  requirements  of  the 
body.  The  following  are  a  few  of  the  new  topics 
interspersed  among  the  old:  rules  for  right  eating; 
balanced  menus ;  food  for  bulk ;  food  waste ;  why  we 
cook  our  food;  pure-food  laws,  and  food  inspection; 
canned  foods ;  patent  medicines ;  mistakes  in  eating ; 


PREFACE  vil 

auto-intoxication,  how  brought  about,  how  avoided; 
headache  and  auto-intoxication;  the  relation  of  alco- 
hol to  taxes,  crime,  and  poverty ;  treatment  of  the  eyes ; 
hygiene  of  the  ear. 

A  new  feature  of  this  book  is  its  chapter  on  sanitation, 
where  contrasts  are  drawn  between  country  conditions 
and  city  surroundings;  between  the  solution  of  sanitary 
problems  for  congested  cities  and  for  scattered  country 
communities. 

Still  another  chapter  shows  how  our  common  microbe 
diseases  —  measles,  scarlet  fever,  malaria,  smallpox,  diph- 
theria, yellow  fever,  etc.  —  are  passed  about,  and  how 
we  may  escape  them  through  vaccination,  antitoxin, 
cleanliness,  and  general  physical  vigor  secured  through 
the  observance  of  the  laws  of  health. 

In  this  volume,  as  in  The  Body  and  its  Defenses, 
tuberculosis  is  studied  —  its  cause,  its  prevention,  and 
its  cure ;  also  typhoid  fever  as  related  to  pure  water  and 
clean  milk;  also  dangers  from  the  public  drinking  cup 
and  the  public  towel,  from  the  fly,  the  mosquito,  the 
hookworm,  and  the  rat. 

These  and  other  related  topics  have  been  brought  to 
the  notice  of  the  students  of  this  volume  with  the  hope 
of  imparting  such  enthusiasm  for  personal  health  and 
such  clear  notions  of  how  to  secure  it  that  healthful 
habits  may  result;  that  the  bodies  of  growing  children 
may  be  strengthened  as  well  as  straightened ;  that  lives 


viii        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

may  thereby  be  lengthened ;  and  that  through  increased 
physical  well-being  the  sum  of  human  happiness  may 
itself  be  increased. 

For  the  convenience  alike  of  teacher  and  of  pupil,  side- 
headings  serve  as  a  ladder  of  connected  topics  through- 
out the  book.  A  series  of  questions  is  also  added  to 
each  chapter,  and  many  illustrations  reenforce  the  teach- 
ings of  the  text.  Special  mention  should  be  made  of 
indebtedness  to  the  American  Journal  of  Physiology 
for  illustrations  used  by  Dr.  Cannon  in  his  article  on 
:t  The  Movements  of  the  Stomach  studied  by  Means 
of  the  Rontgen  Rays,"  and  to  Professor  Chittenden  for 
photographs  of  the  soldiers  with  whom  he  carried  on 
his  food  experiments. 

Other  valuable  illustrations  have  been  reproduced 
from  The  Human  Mechanism  by  Theodore  Hough  and 
W.  T.  Sedgwick,  from  Alcohol  and  the  Human  Body 
by  Sir  Victor  Horsley  and  Mary  D.  Sturge,  and  from 
Unser  Korper  by  F.  A.  Schmidt.  To  each  of  these  and 
to  many  other  important  works  this  small  volume  is  in- 
debted not  merely  for  illustrations  but  also  for  valuable 
facts  which  have  been  used  in  the  preparation  of  its 

subject  matter. 

F.  G.  J. 


CONTENTS 

CHAPTER  PAGE 

I.  CHANGELESS  RECORDS i 

Taking  the  Body's  Record.  When  Cartilage  turns  to  Bone. 
Making  Our  Own  Records.  How  the  Right  Kind  of  Body 
Helps.  Testing  Yourself.  The  Correct  Standing  Position.  The 
Correct  Sitting  Position.  Lateral  Curvature  of  the  Spine.  How 
to  prevent  Lateral  Curvature. 

II.  MUSCLES:    WHAT  THEY  ARE  AND  WHAT  THEY  Do    ...       13 

The  Strong,  Bent  Back.  Effect  of  Work  on  Stretched  Muscle. 
To  Balance  Development.  The  Law  of  Muscle  Change.  One 
Way  of  Developing  the  Muscles.  Antagonistic  Muscles.  Exer- 
cise without  Apparatus.  Studying  Muscle  Structure.  Bundles 
of  Fibers.  Connective  Tissue.  Tendons.  What  makes  Tough 
Muscles.  Two  Classes  of  Muscles.  Weight  of  Muscles. 

III.  BONES  —  THE  FRAMEWORK  OF  THE  BODY 30 

Bones  and  Muscles.  Bone  Structure.  Chemical  Composition  of 
Bones.  Young  and  Old  Bones.  Shape  and  Size  of  Bones.  The 
Spinal  Column.  Wedge-Shaped  Vertebrae.  Bones  Enlarged 
by  Work.  The  Foot  under  Pressure.  The  Bones  of  the  Foot. 
Rules  for  Foot  Hygiene.  Joints  and  their  Ligaments.  The 
Hinge  Joint.  A  Ball-and-Socket  Joint.  The  Synovial  Fluid. 

IV.  THE  HEART  AT  WORK 48 

The  Pulse.  The  Pulse  Beat  and  the  Heart  Beat.  The  Effect 
of  Exercise  on  the  Heart.  What  the  Pulse  Beat  Proves. 
The  Heart  Muscle.  Overtaxing  the  Heart.  Training  Heart  and 
Muscles  Together.  Overstretching  the  Heart.  Heart  Develop- 
ment. Harvey's  Discovery.  Arterial  and  Venous  Blood.  Ar- 
teries and  Veins.  The  Work  of  the  Heart.  The  Use  of 
Valves  in  the  Veins.  Experiments  with  the  Blood  Flow. 


x  PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


The  Structure  of  the  Heart.  The  Double  Work  of  the  Heart. 
Capillary  Connections.  The  Circulatory  System.  Corpuscles 
in  the  Capillaries.  The  Blood  Supply.  Exercise  and  the 
Blood  Supply. 

V.  NICOTINE  AND  THE  SPHYGMOGRAPH 73 

Tests  with  the  Sphygmograph.  General  Effects  of  Smoking. 
Effect  of  Smoking  on  the  Heart.  The  Tobacco  Heart.  How 
Nicotine  gets  to  the  Heart.  Effect  of  Nicotine  on  the  Heart. 
Dr.  Seaver's  Tests. 

VI.  BLOOD  AND  LYMPH  INSIDE  AND  OUTSIDE  THE  TUBES    .       82 

Blood  Examination.  Coagulation.  Blood  under  the  Micro- 
scope. The  Blood's  Important  Work.  Exchanges  along  the 
Tubes.  Gas  Exchanges  in  the  Blood.  Lymph  and  Oxidation. 
The  Lymphatic  System. 

VII.  ALCOHOL  IN  THE  BLOOD  STREAM 95 

Slow  Circulation  of  the  Blood.  Alcohol  and  the  Heart  Beat. 
Testing  the  Heart  Beat  with  the  Sphygmograph.  Alcohol 
and  Heart  Vigor.  First  Effects  of  Alcohol.  The  Real  Harm 
of  Alcohol.  Fat  about  the  Heart.  Weakened  Heart  and 
Arteries. 

VIII.  TRAINED  AND  UNTRAINED  LUNGS 103 

What  is  Breathlessness?  The  Cause  of  Breathlessness.  Speed 
and  Breathlessness.  Tests  of  Chest  Capacity.  Increasing  the 
Chest  Girth.  Structure  of  the  Lungs.  Work  of  the  Lungs. 
Inactive  Air  Sacs.  Health  and  Exercise.  The  Breathing 
Apparatus.  Clean  Air  for  the  Lungs.  Value  of  Moist  Air. 
Getting  an  All-round  Development. 

IX.  EATING  AND  OUR  FOOD  SUPPLY 121 

Experiments  in  Eating.  What  Food  does  for  the  Body.  The 
Five  Food  Substances.  Studying  the  Cost  of  Foods.  Plants 
as  Food  Producers.  Carbohydrate  for  Energy.  The  Proteids. 
Proteid  for  Tissue  Building.  The  Fats.  The  Minerals.  Need 
of  Drinking  Water.  Rules  for  Right  Eating.  Balanced  Menus. 
Food  for  Bulk.  Vegetarians.  The  Teeth. 


CONTENTS  xi 

CHAPTER  PAGE 

X.  FROM  FOOD  TO  BLOOD,  OR  THE  PROCESS  OF  DIGESTION  138 
Food  Experiments  with  Cats.  Under  the  X  Ray.  The 
Stomach  during  Digestion.  Entrance  and  Exit  of  Food.  Use 
of  Bismuth.  Undigested  Substances.  Emotions  that  Hinder 
Digestion.  Happiness  and  Good  Digestion.  When  to  take 
Exercise.  The  Digestive  Apparatus.  Peristaltic  Action  and 
the  Villi.  Activity  in  the  Food  Tube.  Relation  of  Chyle  to 
the  Villi.  Food  Waste. 

XI.  CHEMICAL  ACTION  AND  DIGESTIVE  FLUIDS 154 

The  Chemical  Fluids  of  Digestion.  Number  and  Structure 
of  the  Villi.  Mistakes  in  Eating.  Appetite  and  Gland  Activ- 
ity. Flow  of  Saliva.  Saliva  and  Carbohydrate.  Milk  Diges- 
tion. Proteid  Digestion.  Effect  of  Appetite  on  Digestion. 
Why  we  Cook  our  Food.  Harmful  Substances. 

XII.  LARGE  GLANDS:  THEIR  USE  AND  ABUSE 168 

The  Liver  —  what  it  Is  and  what  it  Does.  Effects  of  Alcohol 
on  the  Liver.  The  Kidneys  —  what  they  Are  and  what  they 
Do.  Effects  of  Alcohol  on  the  Kidneys.  Auto-intoxication. 
How  to  prevent  Auto-intoxication.  Headache  and  Auto- 
intoxication. Other  Glands.  Ill  Effects  of  Snug  Garments. 
Importance  of  Loose  Clothing.  The  Two  Body  Cavities. 
The  Rhythmic  Movement  of  the  Diaphragm.  Aid  to  the 
Organs  of  Excretion. 

XIII.  WHY  NATIONS  RID  THEMSELVES  OF  ALCOHOL    .     .     .     .     186 

France  and  the  Liquor  Problem.  The  German  Attitude. 
Russia  and  Prohibition.  The  English  Method.  The  Japanese 
Liquor  Law.  The  Movement  in  America.  The  Island  of 
Newfoundland.  Taxes,  Crime,  and  Poverty. 

XIV.  BODY  TEMPERATURE  AND  THE  SKIN;  OR  WORK,  HEAT, 

AND  FUEL 194 

Testing  the  Effect  of  Heat  on  the  Body.  Sweat  Glands  as 
Protectors.  Important  Facts  about  the  Skin.  What  the  Skin 
Does.  Taking  Cold.  Symptoms  of  a  Cold.  To  Check  a  Cold. 
To  Prevent  a  Cold.  Internal  Temperature.  Warm-blooded 


xii          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


animals.  Why  Clothes  are  Needed.  Warmth  through  Exer- 
cise. Food  as  Fuel.  To  Reduce  Fat.  Educating  the  Body 
to  Adjust  Itself. 

XV.  THE  NERVOUS  SYSTEM 211 

The  Value  of  Sensations.  The  Hedge  of  Nerve  Warnings. 
What  Nerves  are.  Work  of  the  Fibers.  Different  Sets  of 
Fibers.  Stimuli.  Distribution  of  Nerves.  Memory  and  the 
Cerebrum.  Structure  of  the  Brain.  Cerebrum,  Cerebellum, 
and  their  Convolutions.  The  Gray  and  the  White  Brain  Stuff. 
Centers  in  the  Cerebrum.  How  the  Skull  protects  the  Cor- 
tex. Nerve  Machinery.  Spinal  Nerves.  What  Accidents 
teach  us  about  Nerves.  Truthful  and  Untruthful  Messages. 
Structure  of  the  Neuron.  Nerve  Telegraph  Stations.  What 
the  Gray  and  White  Substances  are.  Fatigue  and  its  Remedy. 

XVI.  TRAINING  THE  CEREBELLUM  AND  THE  SENSES    .     .     .     233 

The  Work  of  the  Cerebellum.  Training  the  Neurons.  Re- 
sults of  Training  the  Neurons.  Neurons  and  Facial  Expres- 
sion. Four  Great  Truths  about  Neurons.  Training  the 
Senses.  Machinery  of  the  Senses.  The  Brain  the  Center 
of  the  Senses.  Enlargement  of  Sense  Centers.  The 
Sense  Centers  of  Laura  Bridgman.  Structure  of  the  Eye. 
Treatment  of  Eyes ;  Headache,  Eyestrain,  etc.  Structure 
of  the  Ear.  Hygiene  of  the  Ear.  The  Sense  of  Smell. 
The  Sense  of  Taste.  The  Sense  of  Touch. 

XVII.  HAPPINESS,  HEALTH,  AND  THE  SYMPATHETIC  GANGLIA     252 

Vital  Activities  Independent  of  our  Will.  Vital  Activities 
Controlled  by  the  Ganglia.  Structure  of  the  Sympathetic 
Nervous  System.  A  Nerve  Plexus.  Good  Temper  and  Di- 
gestion. Why  Happiness  Helps  the  Body.  Service  from 
the  Ganglia. 

XVIII.  ALCOHOL  AND  EFFICIENCY 260 

Tests  made  with  Students.  Tests  made  with  Typesetters. 
Experiments  with  Soldiers.  Alcohol  and  the  Neuron. 


CONTENTS  xiii 

CHAPTER  PAGE 

XIX.  THE  MENACE  OF  THE  MICROBE 267 

The  Public  Drinking  Cup.  What  a  Microbe  Is.  How  Mi- 
crobes Attack  the  Body.  Protection  for  the  Eyes.  Why  we 
Object  to  Flies.  What  Flies  Eat.  Safety  through  Carefulness. 

XX.  SANITATION 277 

Country  Conditions.  City  Surroundings.  The  Meaning  of 
Sanitation.  Cleanliness  the  Watchword.  Sunshine  and  Air 
in  Country  and  City.  Rear  Tenements  and  the  Death  Rate. 
New  Tenement  Regulations.  Parks,  Playgrounds,  etc.  The 
Sewage  System.  Pure- Food  Laws  and  Food  Inspection. 
Danger  from  Dyes.  Canned  Food.  Patent  Medicines. 

XXI.  OUR  FOE  —  THE  TUBERCLE  BACILLUS 289 

Ravages  of  Tuberculosis.  Dr.  Koch's  Discovery.  Records 
from  "  Lung  Block."  East-Side  Conditions.  The  Tubercle 
Bacillus :  how  Lodged  and  Distributed.  The  Nature  of  the 
Microbe.  Bacilli  in  the  Lungs.  Danger  from  Sputum. 
Tuberculosis  of  the  Bones.  Consumption  not  Inherited. 
War  against  the  Enemy.  The  Anti-Tuberculosis  Crusade. 
Carelessness  in  Public  Places.  Public  Sentiment.  Rules  of 
Prevention.  Cure  for  Tuberculosis.  Safety  for  Others.  Five 
Tuberculosis  "  D's."  Outdoor  Air.  Sleeping  Outdoors  in 
Winter.  Open-Air  Classes. 

XXII.  THE    CHOICE:     PURE    WATER   AND    CLEAN    MILK   OR 

TYPHOID  MICROBES  AND  TYPHOID  FEVER     .     .     .     308 

Former  Conditions  in  Pittsburgh.  Explanation  of  the  Death 
Rate.  How  Typhoid  Microbes  reached  Pittsburgh.  Mi- 
crobes and  Drinking-Water.  Safety  through  Sand  Filters. 
Lake  Water  for  Drinking.  Danger  from  Well  Water. 
Sources  of  City  Water.  Rain  Water.  Typhoid  Epidemic 
from  Milk.  Conditions  of  Clean  Milk.  Unclean  Milk. 
Boiling  Milk  to  kill  Microbes.  Pure  Milk  for  Babies. 

XXIII.  CAUSE  AND   PREVENTION,  OR    SAFETY   FROM    MICROBE 

DISEASES 322 

Preventable  Diseases.  Measles  and  Scarlet  Fever.  Small- 
pox. Diphtheria.  Hydrophobia.  Yellow  Fever  and  Malaria. 


xiv         PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

CHAPTER  PAGE 

The  Hookworm  Disease.  Rules  for  those  living  in  Hook- 
worm Regions.  Whooping  Cough  and  Mumps.  Pneu- 
monia. Pink  Eye  and  Trachoma.  Disinfection  and 
Antiseptics. 

XXIV.  MAN'S  FRIEND  AND  DEFENDER  —  THE  PHAGOCYTE      .     338 

Cholera  Microbes  and  the  Phagocyte.  How  the  Phagocyte 
captures  Microbes.  How  Phagocytes  Travel.  Vigorous  and 
Feeble  Phagocytes.  The  Phagocyte  as  a  Scavenger.  What 
Pus  Is.  Cholera  Epidemic  and  Alcohol.  Hydrophobia  and 
Alcohol.  Alcohol  and  the  Phagocyte.  Phagocytes  that 
Multiply  for  Emergencies.  The  Conqueror  of  the  Phagocyte. 
The  Man  who  Drinks. 

BIBLIOGRAPHICAL  LIST 351 

GLOSSARY 353 

INDEX 361 


PHYSIOLOGY,  HYGIENE 
AND  SANITATION 


CHAPTER  I 
CHANGELESS  RECORDS 

Taking  the  Body's  Record.  Certain  cities  are  able  to 
keep  changeless  records  of  their  criminals  who  have 
been  captured.  City  officials  i 
measure  each  man  carefully 
—  his  height  in  standing 
and  in  sitting;  the  distance 
from  the  outstretched  finger 
tip  of  one  hand  to  the  out- 
stretched finger  tip  of  the 
other;  the  length  and  width 
of  head,  face,  and  right  ear ; 
the  length  of  left  foot,  of 
left  middle  finger,  and  of 
left  forearm.  Scars  are  no- 
ticed and  recorded;  also 
the  color  of  hair  and  eyes,  TAKING  H1S  RECORD  WHEN  SEATED 
the  shape  of  the  nose,  the  number  of  teeth,  etc.  Each 
item  is  important  as  part  of  the  final,  full  record 


t 


PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

In  addition,  a  photo- 
graph is  taken.  And, 
strange  though  it  may 
seem,  a  photograph  is  less 
important  than  measure- 
ments in  identifying  a 
man  if  he  is  ever  arrested 
again  and  brought  to  the 
police  station.  The  reason 
is  that  our  bone  measure- 
ments change  little  after 
we  are  twenty-two.  Ever 
and  head,  the  length  of 


A  CALIPER  COMPASS  MEASURES  THE 
LENGTH  OF  HIS  HEAD 


after    that   the    size    of   face 
arms,    of    fingers,    and    of 
legs,  remain  practically  un- 
changed. 

This,  then,  is  a  sure 
and  sensible  way  of  keep- 
ing the  record  of  a  man. 
When  a  criminal  is  under 
examination,  no  matter  how 
violently  he  declares  that 
he  has  never  been  arrested 
before,  the  officers  measure 
him  at  once,  then  search 

their  written  records.    If  they  find  any  set  of  measure- 
ments which  is  a  duplicate  of  those  just  taken,  all  the 


THE  MIDDLE  FINGER  is  MEASURED 


CHANGELESS  RECORDS  3 

man's  denials  are  in  vain.  Those  officers  know  that  never 
yet  have  two  people  been  found  who  had  precisely  the 
same  dimensions  for  all  the  bones  which  were  measured. 

It  takes  but  ten  minutes 
for  the  officers  to  get  their 
record  of  a  man  —  photo- 
graph and  all.  But  it  took 
the  man  himself  twenty-two 
years  to  form  the  body  which 
is  now  his  physical  record 
of  himself;  and  the  training 
began  when  he  was  very 
young. 

When  Cartilage  turns  to 
Bone.  Notice  any  careful 
mother  with  a  baby  in  her 
arms.  See  her  firm  hand 
against  the  back  of  the  head 
as  she  holds  the  child  up  for 
a  look  at  the  world.  She 
knows  that  for  months  there 
is  more  cartilage  than  bone 

in  the  supports  of  a  baby's  body,  and  that  while  bones 
are  in  this  condition  they  cannot  be  trusted  to  do  in- 
dependent work. 

Certain    Indians  have  known  this  for  centuries.     A 
famous    tribe    that    admired    flat-headed    men    secured 


CHINOOK  BABY  IN  HIS  CRADLE 

The  weight  on  his  forehead  will  help 
turn  him  into  a  flat-headed  Indian 


4  PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

these  heads  for  their  boys  by  a  clever  contrivance. 
They  simply  fastened  a  board  by  a  hinge  to  the  head 
of  the  cradle  and  allowed  it  to  press  down  upon  the 
forehead  of  the  baby  whenever  he  was  strapped  in 
place.  As  months  passed,  the  small  skull  not  only  con- 
tinued to  grow  but  also  set  itself  hard  and  firm  in  the 
desired  shape.  And,  once  firmly  set,  there  was  never 
any  hope  that  the  grown  Indian  could  restore  his  head 
to  the  perfect  shape  which  it  had  when  he  was  born. 
Thus  some  of  our  bones  and  muscles  are  trained  by 
other  people  before  we  are  old  enough  to  make  decisions 
for  ourselves.  Yet,  whoever  is  responsible  for  results, 
two  laws  of  bone  growth  should  never  be  forgotten : 

1.  Many  bones  can  be  compelled  to  take  a  bend 
in  this  direction  or  that  while  the  child  is  growing. 

2.  Almost  no  bone  can  be  forced  to  make  a  new 
bend  after  it  is  twenty  years  old. 

But  there  is  other  training  which  is  more  complex, 
and  for  which  we  ourselves  are  responsible. 

Making  Our  Own  Records.  On  a  certain  day  two  boys 
entered  the  same  shop  and  asked  for  work.  The  first 
boy  was  refused,  the  second  was  accepted.  And  the  ex- 
planation lay  with  the  bones  and  the  muscles,  which  had 
made  different  records  for  the  two  bodies.  The  first  boy 
walked  with  a  shuffle  and  had  a  slouching  body.  Before 
he  had  spoken  a  word  the  business  man  who  met  him 
was  unfavorably  impressed  and  ready  to  reject  him. 


CHANGELESS  RECORDS  5 

The  second  boy  walked  as  if  he  respected  his  body 
thoroughly.  His  head  was  erect,  his  shoulders  well 
squared,  and  the  vigor  of  his  body  gave  the  impression 
that  he  was  in  the  habit  of  doing  things  with  energy.  This 
boy  was  accepted  as  promptly  as  the  first  was  refused. 

How  the  Right  Kind  of  Body  Helps.  Let  two  women 
enter  a  store  or  a  schoolroom,  a  theater  or  a  church. 
Which  will  be  served  most  quickly,  she  who  shuffles 
as  she  walks,  has  crooked  shoulders  and  a  head  thrust 
forward,  or  the  woman  who  steps  forward  gracefully, 
who  walks  as  if  her  body  were  under  her  command,  as 
if  it  were  her  true  representative  ?  Surely  the  second 
woman  is  queen  wherever  she  goes.  Without  question, 
at  every  stage  of  growth  the  body  proclaims  the  story 
of  what  has  happened  to  it  and  of  all  that  it  has  done 
with  itself  since  it  began  to  live.  It  is  also  true  that 
we  have  it  more  or  less  within  our  own  power,  while 
we  are  growing,  to  make  the  records  which  are  to 
represent  us  the  rest  of  our  lives. 

If  a  man  by  his  own  acts  or  his  own  carelessness 
must  live  miserably  in  a  shanty  when  he  might  have 
lived  gloriously  in  a  palace,  we  are  apt  to  blame  him 
more  than  we  pity  him. 

Testing  Yourself.  For  the  sake  of  making  discov- 
eries about  yourself,  stand  before  a  mirror  and  study 
the  outlines  of  your  back,  your  chest,  your  shoulders, 
and  your  legs.  Try  to  stand  precisely  as  you  do 


6  PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

every  day  at  home  and  at  school,  so  that  you  may 
get  a  correct  notion  of  the  records  your  bones  and 
muscles  have  made  for  you  thus  far  in  your  life. 


HE  STANDS  WELL 

Notice  his  chest  and  his 
shoulders 


THE  SAME  BOY  AT  ANOTHER 
TIME 


He  lessens  his  lung  capacity 

Be  keenly  critical.  Are  you  standing  squarely  on  both 
feet?  Are  your  knees  bent  or  straight?  Is  your  back 
erect  enough  to  hold  your  head  up  where  it  belongs,  or 
does  your  head  droop  forward  so  that  your  chin  sticks 
out  too  far?  Is  one  shoulder  higher  than  the  other? 
Is  your  'chest  rounded  out  like  that  of  a  soldier,  or  does 


CHANGELESS  RECORDS 


it  sag  like  a  valley  between  your  shoulders?  Rub  your 
hand  across  your  back  to  see  whether  or  not  a  corner  of 
a  shoulder  blade  reaches  out,  like  a  young  wing  starting 
from  the  wrong  place. 

If  you  can  give  creditable  answers  to  these  questions, 
your  future  course  is  easy.  Simply  keep  on  growing  as 
you  have  begun,  and  in  the 
course  of  time  you  will  have 
the  shape  you  wish.  If,  on 
the  other  hand,  you  are  dis- 
satisfied with  what  you  see, 
put  each  point  right  while 
still  looking  at  yourself  in 
the  mirror. 

The  Correct  Standing  Posi- 
tion. Stand  with  both  feet  on 
the  floor,  each  bearing  its 
own  share  of  weight,  both 
knees  unbent,  both  shoulders 
square  and  on  a  level  with 

each  other.  Draw  in  your  chin  until  the  back  of  your 
neck  would  touch  a  stand-up  collar.  Inhale  a  breath 
so  full  and  deep  that  your  chest  looks  like  that  of  a 
drum  major  in  his  regimentals.  Now  your  back  has 
its  correct  shape  for  standing. 

The  Correct  Sitting  Position.     Make  another  test.   Sit 
with  feet  squarely  on  the  floor,  back  straight,  head  erect, 


BACK  VIEW 

Notice  his  shoulders  and  his 
curved  backbone 


8 


PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


and  chest  raised.    Are  you  comfortable  ?     Can  you  draw 
a  full,  deep  breath?    Test  this  thoroughly. 

Now  slip  down  in  your  seat,  curve  your  neck  forward, 
let  your  back  be  bent,  let  your  chest  fall  in,  and  once  more 


RIGHT  POSITION  FOR  READING 

His  lungs  have  ample 
space 


WRONG  POSITION 

He  curves  his  back  and  crowds 
his  lungs 


try  to  take  a  full,  deep  breath.    Notice  that  you  cannot 
do  this  now,  because  you  have  cramped  your  lungs. 

Sit  now  with  one  elbow  on  the  desk,  or  with  one  foot 
drawn  up  under  you,  or  with  some  bend  at  the  waist 
line  that  will  give  a  twist  to  the  spine  near  the  hip. 
The  objection  to  taking  any  one  of  these  as  the  usual 
position .  is  that  gradually  the  relation  of  the  bones  to 


CHANGELESS  RECORDS  9 

each  other  will  be  so  altered  as  to  distort  the  body. 
In  no  wise  does  it  harm  any  of  us  to  twist  this  way 
and  that,  to  bend  as  far  as  we  can  in  one  direction  or 
another.  Indeed,  all  such  exercise  is  good  for  the  body, 
provided  no  position  is  taken  often  enough,  and  held 
long  enough,  to  become  habitual. 

Lateral  Curvature  of  the  Spine.  Dr.  F.  A.  Schmidt,  a 
scientific  writer  in  Germany,  says  that  Dr.  W.  Mayer 
examined  the  backs  of  three  hundred  and  thirty-six  girls 
and  found  that  one  hundred  and  eighty-nine  of  the 
number  had  what  is  called  lateral  curvature  of  the 
spine.  He  found  that  girls  between  seven  and  thirteen 
years  of  age  had  much  more  trouble  than  those  who  were 
under  seven,  and  he  concluded  that  the  habits  of  sitting 
formed  at  the  school  desk  explained  the  difference,  be- 
cause the  older  children  had  spent  more  hours,  days,  and 
years  in  the  schoolroom  than  those  who  were  younger. 

Follow  for  yourself  the  work  of  muscle  and  bone,  and 
understand  what  happens  when  a  child  gets  into  the 
habit  of  sitting  at  his  desk  with  elbow  up  on  one  side, 
shoulder  lifted,  and  body  half  screwed  round.  Notice 
that  if  you  tip  up  one  hip  the  spine  curves  sidewise, 
as  a  balance.  If  you  raise  one  shoulder,  it  pulls  the 
spine  accordingly.  Evidently  each  separate  movement 
of  the  muscles  of  the  back  influences  the  curves  of 
the  spine,  and  the  same  curves  repeated  day  after  day 
at  the  same  desk  mold  the  bones,  and  the  cartilage 


10          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

which  lies  between  them,  in  wrong  positions  until  they 
are  as  truly  pressed  into  a  new  shape  as  if  the  change 
were  planned  for. 

The   main  objection  to   such  curves  is  that  if  they 
are  allowed  to  remain  and  to  become  habitual,  they  will 

interfere  with  the  success- 
ful working  of  the  large 
organs  of  the  body.  Then, 
too,  when  a  curve  becomes 
permanent  —  although  it 
may  be  small — the  nerves 
themselves  are  often  af- 
fected by  it,  and  the 
body  suffers  at  the  point 
which  is  supplied  by  these 
nerves.  A  person  endur- 
ing this  pain  may  not 
know  its  cause,  but  his 
ignorance  will  not  save 
him  from  suffering. 
How  to  prevent  Lateral  Curvature.  Let  us  form  habits 
that  will  help  us  to  prevent  spinal  curvature.  Children 
may  save  themselves  by  being  careful  to  balance  the  ex- 
ercises which  they  allow  the  muscles  of  their  backs  to 
take.  All  that  is  needed  is  a  little  knowledge  and  a  firm 
purpose.  Whoever  allows  himself  to  be  shaped  by  unde- 
sirable-habits of  muscle  and  bone  will  have  cause  for 


BAD  FOR  THE  BACK 

If  this  position  is  taken  every  day  for 

long  periods,  the  vertebrae  will  become 

wedge-shaped 


CHANGELESS  RECORDS  II 

keen  regret  in  later  years.  But  he  who,  in  his  youth, 
controls  his  habits  and  shapes  his  body  with  care  will 
never  regret  it.  Instead,  he  will  have  a  body  that  will 
be  an  honor  to  him  for  the  rest  of  his  life.  Four  rules 
will  help: 

1.  Do  not  sit  day  after  day  in  the  same  twisted 
position.    Change  frequently. 

2.  Do  not  carry  a  heavy  weight  of  books  on  the 
same  arm  back  and  forth  from  school  every  day. 
Carry  as  few  books  as  possible,  and  let  each  arm 
do  its  share  of  the  work. 

3.  Do  not  carry  a  baby  brother  or  sister  on  the 
same  hip  every  day.    Indeed,  it  is  best  to  do  little 
carrying   on  either   hip.    The  weight,   placed   just 
there,  will  tend  to  give  a  wrong  twist  both  to  your 
back  and  to  his. 

4.  If    you    must    stand   for   hours   at   a   stretch, 
learn  to   rest  one  leg  by  using  the  other.     Don't 
let  one  side  sag  down  habitually.    Change  sides. 

QUESTIONS 

1.  How  do  cities  get  and  keep  records  of  criminals  ?  2.  Which  is  the 
more  accurate  record  of  a  person  —  a  photograph  or  measurements  ? 
3.  After  what  age  are  bones  set  for  life  ?  4.  Why  does  a  mother  sup- 
port the  head  of  a  young  baby  when  holding  it?  5.  Give  two  laws  of 
bone  growth.  6.  What  effect  does  an  erect,  healthy  body  have  on  a 
boy's  chance  of  success?  7.  In  what  ways  does  the  body  tell  facts 
about  us? 


12  PHYSIOLOGY,  HYGIENE,  AND   SANITATION 

8.  Test  your  own  body  to  see  if  you  stand  correctly.  9.  What 
sitting  positions  are  objectionable,  and  why?  10.  What  difference  is 
there  between  sitting  with  a  twist  in  the  back  once  in  a  while  and 
taking  that  position  most  of  the  time?  11.  What  must  be  guarded 
against?  12.  Do  older  or  younger  girls  have  more  trouble  from  lateral 
curvature  of  the  spine?  13.  Why  is  this?  14.  Mention  various  posi- 
tions that  bring  curves  to  the  spine.  15.  What  objection  is  there  to 
these  curves  ?  16.  Give  four  rules  for  preventing  them. 


CHAPTER   II 

MUSCLES:    WHAT  THEY  ARE  AND  WHAT  THEY   DO 

The  Strong,  Bent  Back.  The  coal  heaver  round  the 
corner  has  a  superb  set  of  muscles  over  the  working 
part  of  his  back.  They  are  so  well  developed  that,  as 
he  stands  bent  over  his  work, 
it  is  evident  that  these  mus- 
cles give  him  a  back  of  tre- 
mendous strength.  By  their 
help  he  shovels  coal  for  hours 
at  a  time,  through  the  days 
and  weeks  of  the  year.  More- 
over, when  he  has  finished 
his  day's  work  he  does  not 
seem  overtired.  He  even  jokes 
at  the  expense  of  his  own 
back,  for  although  it  is  so 
well  developed  and  so  tire- 
less, still  the  man  himself  BENT  BY  HIS  WoRK 
frankly  acknowledges  that  it  is  sadly  bent,  and  that  by 
no  effort  on  his  part  can  he  stand  straight  or  walk  as 
would  please  him  best.  He  says  that  this  is  the  price 
he  has  had  to  pay  for  the  kind  of  work  he  has  chosen. 

13 


14          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Multitudes  of  people  have  round  shoulders  developed 
in  some  such  way  as  this.  Notice  their  shape,  know 
about  their  occupations,  and  draw  your  own  conclusions. 

A  bicycle  rider  whom  I  know 
has  a  back  quite  as  bent,  not  so 
much  from  the  work  it  has  done 
as  from  the  position  it  has  been 
allowed  to  maintain.  It  is  mus- 
cular, strong,  and  efficient,  but  it 
never  looks  well  except  when  he 
is  working  his  legs  fast  on  his 
wheel. 

Something  must  be  wrong,  and 
we  wonder  what  it  is.  Here  are 
these  men,  and  multitudes  of 
others,  whose  backs  are  well  de- 
veloped, but  who  are  so  bent 
as  to  look  almost  deformed.  For 
years  no  one  could  entirely  ex- 
plain the  cause  of  the  combina- 
tion —  a  strong  but  bent  back. 
Close  observation  and  logical  rea- 
soning have  answered  the  ques- 
tion, however,  for  we  learn  that  muscles  stay  in  the 
position  in  which  they  do  their  heaviest  work. 

Effect  of  Work  on  Stretched  Muscle.    A  traveling  man 
whom  I  know  says  that  when,  for  a  few  weeks,  he  carries 


BENT  BY  BICYCLING 


MUSCLES :  WHAT  THEY  ARE  AND  WHAT  THEY  DO 


his  suit  case  persistently  with  his  right  hand,  the  right 
shoulder  becomes  an  inch  or  an  inch  and  a  half  lower 
than  the  other,  while  at  the  same  time  it  becomes  stronger. 
This  shows  that  a  muscle  can  be  lengthened  even 
while  it  is  being  strengthened. 
Two  oarsmen  row  with  all 
their  might.  One  does  it  with 
a  straight  back,  the  other  with 
a  curved  back.  Their  work 
continues  day  after  day,  until 
one  back  is  as  strong  and  as 
muscular  as  the  other.  But  see 
the  results.  One  man  walks  as 
if  he  had  spent  his  boyhood 
curved  over  a  school  desk  with- 
out a  thought  about  what  was 
happening  to  his  spine.  The 
other  man  looks  as  if  he  might 
have  spent  those  same  years  at 
West  Point,  with  officers  and 
fellow  students  who  compelled 
him  to  stand  straight  whether  he  wished  to  or  not. 
Yet  the  boyhood  of  the  two  men  may  have  been 
alike.  The  difference  just  now  depends  upon  their 
postures  while  they  were  rowing.  Their  muscles,  when 
they  walk,  simply  betray  some  facts  about  their  recent 
history. 


BENT  BY  AGE 


1 6          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

To  Balance  Development.  Fortunately,  however,  there 
is  a  happy  outlook  even  for  such  people  as  are  obliged 
to  work  with  their  backs  bent,  for  there  is  another  im- 
portant fact  about  this  law  of  contracting  and  stretching. 
I  give  it  concisely: 

Brief,  vigorous  exercise  in  the  right  position  will  undo 
much  of  the  harm  of  long-continued  exercise  in  the  wrong 
position. 

If  a  man  who  works  in  a  bent  posture  all  day  will 
spend  five  minutes  a  day  in  taking  vigorous  exercise 
with  his  back  straight,  alternately  tightening  hard  and 
then  relaxing  the  muscles  of  his  back  and  neck,  he 
will  find  that  within  one  month  there  will  be  an  im- 
provement. And  the  more  faithfully  the  exercise  is 
continued  afterwards,  the  more  good  will  it  do.  By 
this  simple  device  a  man  may  save  himself  from  his 
rounded  back  and  be  able  to  hold  his  head  where  it 
should  be. 

It  often  happens  that  the  muscles  of  the  chest  be- 
come thin  and  flabby  for  lack  of  exercise,  even  while 
the  back  has  become  very  strong.  But  these  muscles 
may  be  saved.  Throw  the  shoulders  well  back  and  exer- 
cise the  chest  muscles  hard  in  this  position.  Exercise 
them  while  they  are  thus  stretched,  and  they  will  grow 
large  and  prominent  in  spite  of  what  your  occupation 
may  be.  If  the  exercise  can  be  taken  oftener  than  once 
a  day,  it  will  be  so  much  the  better. 


MUSCLES:  WHAT  THEY  ARE  AND  WHAT  THEY  DO      17 

The  Law  of  Muscle  Change.  In  this  work  of  changing 
the  shape  and  the  power  of  a  muscle,  the  greatest  strain 
must  be  put  on  the  last  third  or  the  last  quarter  of  the 
contraction.  Remember  that  each  muscle  is  inclined  to 
stay  in  the  shape  which  it  takes  when  it  does  its  hardest 
work;  in  other  words,  the  law  is  that  doing  a  thing 
makes  the  part  shape  itself 
for  that  act.  Evidently,  then, 
to  a  large  extent,  we  may 
develop  our  bodies  accord- 
ing to  our  desire.  Knowing 
this,  a  public  lecturer  —  a 
doctor  —  told  his  audience 
that  each  man  present  could 
increase  the  size  of  his  arms 
three  quarters  of  an  inch 
within  one  month  and  could 
increase  his  chest  measure 
an  inch  and  a  half  during 
the  same  length  of  time. 

One  Way  of  Developing  the  Muscles.  To  show  what  he 
meant,  the  lecturer  asked  his  friend,  a  medical  student, 
to  illustrate  the  points  one  by  one  as  he  himself  ex- 
plained them.  The  student  was  well  knit  and  well  built, 
no  unnecessary  fat  concealed  the  shape  of  his  muscles, 
and  he  was  ready  to  show  the  other  men  what  they  also 
might  do  in  behalf  of  their  own  development. 


1 8        -  PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

"  Now,"  said  the  doctor,  "  show  us  the  effect  on  the 
biceps  of  rotating  the  arm;  the  forearm;  now  rotate 
the  leg  —  the  big  muscles;  show  that  tensor.  Now 
again  will  you  go  through  four  or  five  exercises  that 
bring  into  play  in  succession  first  one  arm,  then  the 
other,  and  so  on  ?  " 

The  student  acted  on  the  suggestions  as  fast  as 
they  were  given.  His  smooth  back  and  arms  gave 

no  sign  of  separate  muscles 
while  he  stood  quietly  wait- 
ing to  be  told  what  to  do, 
but  as  soon  as  he  followed 
directions  and  used  arm, 
leg,  back,  or  shoulders,  there 
sprang  into  prominence  one 
set  of  well-developed  muscles 

WELL-DEVELOPED  MUSCLES  ^^  anothen 

Antagonistic  Muscles.  The  student  held  no  apparatus, 
but  used  arms  and  legs  as  if  he  were  pulling  against 
some  invisible  weight.  He  was,  in  fact,  pulling  against 
the  force  of  his  other  muscles  —  antagonistic  muscles, 
they  are  called.  Try  this  for  yourself,  with  your  forearm 
or  with  your  back.  Try  to  bring  out  one  muscle  and 
see  how  many  others  are  called  into  action.  The  doctor 
then  explained  that  muscles  can  be  developed  in  this 
way  with  no  apparatus  whatever.  "  Muscles,"  said  he, 
"can  pull  in  one  direction  only;  the  opposite  pull  has 


EXERCISE  WITHOUT  APPARATUS 


MUSCLES:  WHAT  THEY  ARE  AND  WHAT  THEY  DO      19 

to  be  done  by  antagonistic  muscles."    He  made  it  plain 
that  in  arms,   legs,   and   elsewhere,   muscles   are   often 

placed  in  pairs,  called  flexors 
and  extensors,  which  balance 
each  other  with  their  power 
of  pulling.  He  showed  that 
these  opposing  muscles  can 
be  developed  without  appara- 
tus by  making  flexor  muscles 
bend  the  limb,  and  extensors 
straighten  it  out  again.  It  is 
flexor  and  extensor  muscles 
that  help  us  close  and  open  our  hands ;  help  us  curl 
up  our  toes  and  stretch  them  out  again  vigorously. 

Exercise  without  Appara- 
tus. As  he  went  on  with  his 
address,  the  doctor  said  that 
to  make  muscles  develop, 
they  should  pull  as  hard 
as  possible  for  a  few  seconds 
at  a  time,  then  let  go  com- 
pletely, then  pull  again  for 
a  few  seconds,  and  so  keep 
up  the  alternation  for  five 
minutes  in  the  morning,  for  five  minutes  at  night,  and 
for  ten  minutes  a  day  between  times.  '  To  develop 
arm  or  chest,"  said  he,  "put  in  the  extra  ten  minutes 


HE  DEVELOPS  ARM  MUSCLES 


20          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

whenever  convenient."  It  appears,  therefore,  that  in 
many  cases  the  process  of  developing  one  muscle  or 
set  of  muscles  may  be  carried  on  without  apparatus 
and  without  the  gymnasium. 

Examine  your  own  muscles.  Decide  which  are  firm, 
which  flabby.  If  they  should  be  improved,  talk  the 
matter  over  with  any  good  gymnasium  director.  He 

will  tell  you  what  special 
daily  exercise  to  take  for 
special  muscles.  As  for  se- 
curing very  big  muscles, 
however,  they  are  really  of 
no  advantage  in  the  health 
line.  Still  the  fact  that  up  to 
a  definite  limit  we  have  the 

TAKING  THE  MEASUREMENT  pQwer  t()  increase  the  size  of 

arm  and  chest  and  leg  proves  once  again  how  truly  each 
of  us  is  master  and  architect  of  the  body  we  are  building. 
Studying  Muscle  Structure.  But  what  about  the  sub- 
stance out  of  which  the  body  molds  a  muscle  into 
shape  and  compels  it  to  increase  somewhat  in  size 
whenever  it  is  forced  to  do  unusual  work?  Get  a 
piece  of  lean  corned  beef  from  the  butcher;  have  it 
boiled  thoroughly;  place  a  board  over  it  and  press 
down  upon  it  hard  enough  to  squeeze  out  all  the 
liquid ;  remove  the  board,  and  with  a  needle  of  some 
sort  pick  apart  the  fibers  as  well  as  you  can.  Pick 


MUSCLES :  WHAT  THEY  ARE  AND  WHAT  THEY  DO      2  I 


them  away  from  each  other  into  finer  and  finer  threads 
until  you  think  you  have  reached  the  smallest  ones 
of  all. 

Now,  with  a  good  magnifying  glass,  examine  one  of 
these  bits  of  beef  muscle.  You  are  able  to  pull  them 
apart  because  the 
tough  outside  wrap- 
ping of  each  has 
been  changed  by 
boiling. 

Bundles  of  Fibers. 
However  large  or 
small  a  muscle  may 
be,  and  wherever 
that  muscle  does 
its  work,  whether 
in  creatures  that 
walk,  fly,  or  swim, 
every  bundle  of 
muscle  is  made  up 
of  fibers  wrapped 

together.  Shapes  are  different ;  size  varies  —  from  those 
that  draw  an  eyelid  up  and  down,  to  those  that  kick  a 
football  to  its  goal ;  the  work  of  each  is  different ;  their 
strength  and  power  of  endurance  are  different ;  but  each 
bundle  is  a  combination  of  individual  fibers.  A  few  of 
these  are  wrapped  together  as  a  small  bundle,  small 


MUSCLES  OF  DIFFERENT  SHAPES 


22 


PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


INDIVIDUAL 
MUSCLE  FIBERS 


bundles  are  gathered  into  bundles  that  are  larger,  large 
bundles  become  larger  yet,  and   thus  from  smaller  to 

larger   are   the   muscles    built    up. 

Each  is  a  bundle  of  other  bundles ; 

each  is  adapted  in  size  and  shape 

f~  /    (  r  to  the  special  work  which  it  must 

III  do;  and  every  fiber  in 

the  bundles,  large  and 
small,  is  inclosed  in 
what  is  called  the  sar- 
colemma.  This  sarco- 
lemma,  then,  is  simply 
an  outer  wrap  that 
separates  each  fiber  from  its  neighbors. 

Connective  Tissue.  In  addition,  however, 
there  is  a  close  network  of  substance  called 
connective  tissue,  which  holds  the  individual 
fibers  together.  In  this  connective  tissue 

are  the  tiny  blood 
vessels  and  the  slender  nerves 
which  supply  blood  and  stimu- 
lus to  each  smallest  fiber.  Fine 
threads  of  connective  tissue 
also  stretch  away  from  each 
A  BUNDLE  OF  MUSCLE  FIBERS  end  of  the  muscle  fibers  and 
Each  is  covered  with  its  own  help  to  form  the  tendon.  Each 

sarcolemma;  connective  tissue  is  . 

between  the  fibers  tendon  is  fastened  to  a  bone. 


END  OF  A 
MUSCLE  FIBER 

It    shows    fine 

threads    which 

help   form  the 

tendon 


MUSCLES:  WHAT  THEY  ARE  AND  WHAT  THEY  DO      23 

Tendons.    Any  tough   bundle    of   tough  fibers  which 
holds  muscles  to  the  covering  of  the  bone  is  called  a 
tendon.     Examine    your   wrist.     Open    and    shut    your 
hand  by  the  use  of  extensor  and  flexor  muscles.    Notice 
the  movement  of  the  long  slender  tendons  that  connect 
the  fingers  with  muscles  in  the  arm.   The  foot  is  moved 
by  tendons  that  reach  up  to  the  mus- 
cles of  the  leg.   This  use  of  long  ten- 
dons gives  the  body  its  slender  wrists 
and  ankles.    Some  muscles  end  in  ten- 
dons fastened   to  bones  at  a   distance. 
Some   have   short  tendons   fastened   to 
bones  near  by.     But,  whether   long   or 
short,  whether   large   or  small,  all  ten- 
dons are  needed  to  help  muscles  pull 
the  bones  in  definite  directions.     And     TENDON,  GREATLY 
the  muscle  itself  does  its  work  by  con-         MAGNIFIED 
tracting  and  relaxing.  *£££-" 

Draw  up  the  muscle  in  the  calf  of  the 
leg.  It  has  tendons  fastened  to  the  lower  end  of  the 
thigh  bone  and  to  the  heel  bone.  The  contracting  of  the 
muscle  is  done  between  these  two  firmly  held  points, 
and  because  of  this  contraction  we  are  able  to  walk, 
run,  dance,  and  kick.  The  biceps  muscle  of  the  arm  has 
tendons  which  hold  one  end  of  it  to  the  shoulder,  the 
other  end  to  a  bone  in  the  forearm.  When  the  mus- 
cle contracts,  the  lower  end  is  drawn  up,  not  because 


24          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

the  tendons  contract  but  because  they  cling  to  the 
bones  and  so  do  the  pulling.  The  wonder  is  that  these 
tendons  do  not  more  often  suffer  under  the  sudden 
strain  which  we  sometimes  put  upon  them.  When  they 
do  give  way  —  as  happens  in  a  sprained  ankle  —  it  is 
often  a  more  serious  matter  than  a  broken  bone,  because 

the  outside  covering  of  the 
bone  is  sometimes  pulled 
away  with  the  tendon,  and 
the  ends  of  a  broken  bone 
knit  together  much  more 
easily  than  do  the  torn  ter- 
minations of  a  tendon. 

Remember  that  when  any 
muscle  pulls  any  bone  it  is 
because  each  muscle  fiber 
in  the  bundle  has  shortened 
itself  and  grown  thicker. 
MUSCLE  ENDING  IN  TENDON;  TENDON  Indeed,  it  is  the  shortening 

of  the  fibers  that  compels 
the  pulling.  Double  up 
your  arm  hard  and  prove  this.  The  muscle  is  thicker 
because  of  the  united  work  of  thousands  upon  thou- 
sands of  fibers.  Although  each  separate  fiber,  then,  is 
a  part  of  the  muscle  as  a  whole,  each  is  also  a  small  in- 
dependent center  of  power,  doing  its  own  work.  But  no 
single  fiber  carries  its  independence  very  far.  Generally 


FASTENED   TO    BONE 

(After  Schmidt) 


MUSCLES:  WHAT  THEY  ARE  AND  WHAT  THEY  DO      25 

when  its  neighbors  receive  a  command  to  go  to  work,  it 
receives  the  same  command.  When  they  rest,  it  rests  too. 
When  they  are  destroyed  by  age  or  death,  it  endures  all 
that  they  endure.  Yet,  after  all,  the  work  of  the  millions 
of  fibers  that  are  held  to- 
gether by  connective  tissue 
in  a  single  muscle  is  really 
the  sum  of  the  work  which 
the  fibers  do  separately. 

What  makes  Tough  Mus- 
cles. More  than  this,  it  is 
the  amount  of  connective 
tissue  between  the  fibers 
that  explains  the  difference 
between  tough  and  tender 
meats.  With  age  and  ex- 
ercise this  tissue  gradually 
thickens  its  substance  dur- 
ing life,  until  finally  certain 
muscles  become  too  tough 
to  be  eaten  without  long 
boiling  or  steaming. 

When,  therefore,  we  speak  of  tough  and  tender  meat, 
we  really  refer  to  muscles  in  which  the  connective  tis- 
sue has  or  has  not  been  toughened  by  age  or  exercise. 

Let  an  athlete  bend  up  his  arm.  You  may  try  to 
press  it  with  your  hand,  and  it  will  resist  you  almost 


MUSCLES  TIGHTENED  AND  SHORTENED 
FOR  THE  JUMP 

(After  Schmidt) 


26          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

like  a  piece  of  wood.  This  is  no  mystery,  for  you 
understand  that  each  fiber  in  that  muscle  has  been 
toughened  by  use.  If  such  a  muscle  were  found  in  the 
shop  of  a  butcher  and  offered  for  sale,  a  wise  cook 
would  refuse  to  buy  it,  because  even  boiling  would  not 
make  it  tender.  But  tough  muscle  in  the  arm  of  an 
athlete  means  that  it  is  in  prime  working  condition. 


A  RUNNING  BROAD  JUMP  FROM  ONE  FOOT 

It  shows  the  work  done  by  different  muscles  from  the  moment  the  man  jumped 
until  he  stood  on  his  feet  again 

(After  Schmidt) 

Two  Classes  of  Muscles.  The  muscles  which  we  have 
been  studying  belong  to  the  skeleton.  They  are  always 
attached  to  bones  and  are  therefore  called  skeletal 
muscles.  There  are  two  great  classes  of  muscles : 

I.  Voluntary  muscles,  of  which  there  are  five 
hundred,  are  under  the  power  of  our  will.  Through 
them  we  walk,  run,  climb,  and  swim ;  through  them 
we  talk,  sing,  play  the  piano,  and  crown  ourselves 
with  glory  on  the  athletic  field.  Most  of  them  are 
fastened  to  bones  that  are  movable.  Hand  and 
head,  arms,  legs,  fingers,  mouth,  tongue,  eyelid,  and 
eyeball  —  all  are  under  our  control  because  they  are 


SUPERFICIAL  MUSCLES  OF  THE  BODY 
Each  is  fastened  to  bones  that  lie  underneath 

27 


28          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

moved  by  our  voluntary  muscles,  which  contract 
and  relax  at  our  bidding.  Not  so,  however,  do 
muscles  of  the  other  sort. 

2.  Involuntary  muscles  are  independent  of  the 
bones,  independent  of  our  will,  and  far  too  numer- 
ous to  count.  They  form  the  muscular  sac  of  the 
stomach  and  the  muscular  tube  of  the  intestines. 
They  give  muscular  power  to  the  arteries  and  form 
the  entire  substance  of  the  heart.  It  is,  in  fact,  the 
ceaseless  contracting  and  relaxing  of  the  involuntary 
muscles  of  our  heart  that  keeps  us  alive,  through 
the  circulation  of  the  blood.  When  heart  muscles 
stop,  life  must  soon  stop.  Each  air  sac  of  the  lungs 
has  its  muscular  wall,  and  each  individual  organ  of 
the  body  has  its  own  supply  of  involuntary  mus- 
cles in  constant  service.  All  these  are  deaf  to  our 
commands,  but  they  continue  to  be  busy  whether 
we  sleep  or  wake,  whether  we  stand  or  sit,  walk 
or  run,  whether  we  laugh  or  cry.  Whatever  we  do, 
they  are  unceasingly  occupied  with  the  internal 
work  of  the  body,  pumping  the  blood  through  heart 
and  blood  vessels,  caring  for  the  food  we  eat,  and 
carrying  on  those  vital  processes  over  which  we 
have  no  conscious  control. 

Weight  of  Muscles.  Taken  as  a  whole,  the  muscular 
machinery  of  any  human  being  is  as  heavy  as  all  the 
rest  of-  his  body  weighed  in  a  lump.  A  few  separate 


MUSCLES:   WHAT  THEY  ARE  AND  WHAT  THEY  DO      29 

muscles  are  given  in  the  picture  on  page  27.  Each  does 
its  own  separate  work,  and  all  help  in  what  the  body 
does  for  us.  But  perhaps  the  biceps  is  the  muscle  best 
known  to  every  boy. 

Study  the  muscles  on  the  chart  and  locate  as  many 
of  them  as  possible  on  your  own  body.  The  intercostal 
muscles  do  not  appear,  being  hidden  under  other  mus- 
cles. They  hold  the  separate  ribs  to  each  other. 

QUESTIONS 

1.  Why  do  coal  heavers  have  strong,  bent  backs  ?  2.  What  law 
explains  such  a  back  ?  3.  Mention  such  occupations  as  you  think  may 
change  the  shape  of  the  body.  4.  Give  the  second  great  law  about 
muscles  stretching  and  contracting.  5.  How  may  a  man  who  works  in 
a  bent  position  save  himself  from  being  permanently  bent  ?  6.  How 
can  you  show  what  muscles  can  do  ?  7.  If  a  person  exercises  without 
apparatus,  what  does  he  pull  against  ?  8.  What  is  an  antagonistic  mus- 
cle ?  9.  How  can  muscles  be  developed  without  apparatus  ?  10.  How 
often,  and  for  how  long  a  time,  should  such  exercises  be  taken  ? 

11.  Define  muscle  fiber.  12.  How  may  we  examine  the  structure  of 
a  muscle  closely  ?  13.  Tell  about  the  size  and  shape  of  different  muscles. 
14.  Tell  how  muscles  are  formed.  15.  What  is  the  sarcolemma  ?  16.  What 
is  connective  tissue  ?  17.  What  lies  within  it  ?  18.  Of  what  use  are  the 
fine  threads  of  connective  tissue  that  stretch  away  from  muscle  fibers  ? 
19.  What  do  they  help  form?  20.  What  is  a  tendon?  21.  To  what 
bones  are  the  muscles  in  the  calf  of  the  leg  fastened  ?  22.  What  does 
the  biceps  pull  up  ?  How  ?  23.  Why  is  a  torn  tendon  often  worse  than 
a  broken  bone?  24.  When  is  meat  tough  ?  tender?  25.  Describe  volun- 
tary muscles.  26.  What  is  the  work  of  involuntary  muscles  ?  27.  Com- 
pare the  weight  of  the  muscles  with  that  of  the  rest  of  the  body. 
28.  Study  the  chart  and  name  five  muscles. 


CHAPTER  III 
BONES  — THE  FRAMEWORK  OF  THE  BODY 

Bones  and  Muscles.  A  certain  teacher  who  owned  a 
skeleton  used  to  throw  it  over  his  shoulder  when  he 
carried  it  from  the  storeroom  to  the  lecture  room.  And 
as  he  walked  it  hung  from  his  back,  a  clattering  set  of 
dangling  bones.  It  is  true  that  the  separate  bones  were 
held  together  at  the  joints  by  artificial  contrivances,  but 
that  was  all.  The  skeleton  could  not  have  stood  on  its 
own  unaided  legs.  Those  who  saw  this  group  of  bones 
and  were  instructed,  understood  as  never  before  that 
bones  are  as  dependent  on  ligaments  and  muscle  to 
keep  them  together  as  are  tendon  and  muscle  depend- 
ent on  bone  to  hold  them  in  place. 

Bone  Structure.  Examine  a  bone  fresh  from  the 
butcher's.  Notice  the  outside  —  firm  and  closely  woven, 
as  it  has  to  be  to  supply  a  surface  for  muscles  to  hold 
to.  This  bone-covering  is  the  periosteum.  It  is  a  tough 
membrane,  and  tendons  from  the  muscles  are  fastened 
to  it. 

Within  the  bone  we  find  the  texture  much  looser  than 
that  of  the  periosteum.  We  'know  now  how  it  happens 
that  the  bone  is  not  only  large  and  strong  but  light  and 

30 


K 


THE  HUMAN  SKELETON 

A,  skull  (22  bones) ;  B,  spinal  column  (33  vertebrae) ;  C,  sternum;  £>,  ribs  (12  on 
each  side) ;  E,  clavicle  (i  on  each  side) ;  F,  scapula  (i  on  each  side) ;  G,  humerus ; 
H,  radius;  /,  ulna;  _/,  carpal  bones  (7  in  each  wrist) ;  K,  metacarpal  bones  (5  in 
each  hand);  Z,  phalanges  (14  in  each  hand);  M,  pelvis  (4  bones);  N,  femur; 
O,  patella  (i  in  each  knee) ;  /*,  tibia ;  Q,  fibula ;  A*,  tarsal  bones  (7  in  each  ankle) ; 
S,  metatarsal  bones  (5  in  each  instep) ;  T,  phalanges  (14  in  each  foot) 


32          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

firm.  It  is  indeed  by  no  means  a  solid  substance.  A 
magnifying  glass  shows  numerous  tiny  spaces  in  the 
body  of  the  bone.  One  may  also  see  smooth  channels 
on  the  outside,  along  which  the  blood  vessels  ran,  and 
tiny  openings  from  the  surface  to  the  interior,  into  which 
the  smallest  blood  vessels  went  to  keep  up  the  life  of 

the  bone. 

Chemical  Composition 
of  Bones.  A  chemist 
will  take  a  bone  and 
keep  it  in  acid  for  a 
while.  He  will  then  tell 
us  that  he  has  taken 
out  all  the  lime  salts 
and  has  left  nothing 
but  organic,  or  animal, 
matter.  He  may  now 
tie  the  bone  into  a  knot 
to  show  how  flexible  it 
is.  Taking  another  bone  he  will  hold  it  in  fire  for  a 
while;  then,  when  touched,  the  whole  structure  falls  to 
pieces — a  heap  of  white  powder.  *  This  is  mostly  lime," 
he  says.  "  I  have  burned  out  the  organic  part."  A  cook 
will  take  a  meatless  bone,  boil  it  for  several  hours,  and 
secure  a  jelly  to  add  to  her  soups.  This  is  gelatin  from 
the  animal  matter  of  the  bone.  It  proves  that  even  a 
bone  is  of  value  and  should  not  be  wasted. 


A  B 

BONE  CUT  LENGTHWISE  (A)  AND 
CROSSWISE  (B) 

Blood  vessels  and  nerves  run  through  the 

canals,  and  these  canals  are  joined  to  each 

other  by  channels  yet  more  minute 


BONES  —  THE  FRAMEWORK  OF  THE  BODY 


33 


TIED  IN  A 

After  acid  has 

taken  the  lime 


Young  and  Old  Bones.  These  and  other  experiments 
show  that  bones  are  made  up  of  so-called  lime  and  an  ani- 
mal substance  which  becomes  gelatin  on  being  cooked. 

We  also  learn  that  the  bones  of  old  people 

contain    much    lime   and 

are  very  brittle,  while  the 

bones  of  a  child  contain 

far  less  lime  and  are  less 

brittle.    This  fact  makes 

it  unsafe  for  aged  people 

to  have  even  a  tumble  on 

the     sidewalk.     Younger 

bones  can  save  themselves 

by  bending  a  trifle. 
We  understand  now  why  children 
have  so  much  power  to  shape  their 
bones  while  they  are  young.  It  is  be- 
cause these  bones  are  not  yet  firmly 
set  with  lime. 

Decide  for  yourself  why  each  of 
your  bones  has  its  own  particular 
shape.  Study  the  picture  of  the 
skeleton  and  learn  as  many  of  the 
names  as  your  teacher  requires. 

Shape  and  Size  of  Bones.  Each  bone 
has  its  own  particular  shape:  long 
ones  for  legs  and  arms;  flat  ones  for 


A  BONE  CUT 

THROUGH  LENGTHWISE 


The  outer  layer  is  com- 
pact and  firm,  the  inner 
substance  is  a  network 
of  canals  and  spaces ; 
thus  are  bones  both  light 
and  strong 


PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

shoulder  blades,  breastbone,  and 
hips;  curved  long  ones  for  the 
ribs ;  curved  flat  ones  for  the  skull. 
These  latter  are  so  closely  inter- 
locked that  the  head  seems  like  a 
solid,  single  bone.  There  are  queer, 
jagged  bones,  one  above  the  other 
in  a  column,  for  the  back,  and  many 
small  bones  of  hand  and  foot  deftly 
held  together  by  ligaments.  Each 
bone  does  its  part  in  supporting  the 
muscles  and  other  soft  parts,  and 
in  making  them  serviceable  to  us. 

The  shafts  of  the  long  bones  are 
hollow,  with  delicate  fat,  called  mar- 
row, in  the  center.  The  short,  flat, 
and  square  bones  are  spongy  inside, 
with  red  marrow  in  the  spaces. 

The  human  skeleton  is  made  up 
of  two  hundred  separate  bones,  each 
with  its  special  name.  But  perhaps 
the  most  important  group  is  the 
column  of  vertebrae  which  forms 
the  spine. 

The  Spinal  Column.  Many  a  man 
has  lived  for  years  without  an  arm, 
without  a  leg,  without  bones  of 


LOWER  LEG  WITH  ITS 

MUSCLES  AND  TENDONS 

(After  Schmidt) 


BONES  — THE  FRAMEWORK  OF  THE  BODY 


35 


Cervical 


ft* 


Thoracic 
(orDorsal} 


various  sizes  and  shapes;  but  no  man  would  ever  be 
able  to  live  for  a  moment  without  that  column  of  small 
bones  that  holds  his  head  erect, 
that  keeps  his  ribs  in  place,  and 
that  guards  the  treasure  of  his 
spinal  cord. 

In  the  spinal  column  each  sepa- 
rate vertebra  is  held  to  the  one 
above  it  and  to  the  one  below  it 
by  muscles  and  ligaments  on  each 
side,  and  because  of  their  muscles 
and  ligaments  these  individual  ver- 
tebrae are  no  more  responsible  for 
the  shape  they  take,  or  for  the 
twists  and  curves  they  join  in  mak- 
ing when  a  gymnast  bends  his  back 
from  side  to  side,  than  are  the 
dumb-bells  and  the  pulleys  which 
the  same  gymnast  uses;  for  the 
bones  of  the  spine  simply  rock 
back  and  forth  or  sideways  upon 
each  other,  according  as  muscles 

On      this      side      Or      that      give      the     Each  group  of  vertebrae  has 

needed  pull  and  move  the  bones.  its  special  name 

To  prevent  too  much  jarring,  each  vertebra  is  sepa- 
rated from  its  neighbor  by  a  thin  elastic  cartilage  which 
acts  like  a  cushion  between  them. 


Lumbar 


Sacral 


A  SIDE  VIEW  OF  THE 
SPINAL  COLUMN 


PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


VERTEBRA  SEEN  FROM 
ABOVE 


Wedge-Shaped  Vertebrae.  Just  here  recall  a  few  facts. 
Young  bones  are  somewhat  yielding;  they  take  new 
shapes  if  they  are  put  under  special,  oft-repeated  pres- 
sure. A  child  at  a  school  desk 
easily  gets  into  the  habit  of  sit- 
ting with  the  vertebrae  pressed 
against  each  other  at  the  same 
angle  every  day.  Muscles  do  the 
pulling ;  they  grow  strong  as  they 
are  exercised.  In  the  meantime, 
also,  the  separate  vertebrae  are 
yielding  to  pressure.  On  one  side 
they  are  growing  thinner;  on  the  other  side,  not  being 
pressed  upon,  they  grow  thicker.  The  result  is  that  some 
of  the  bones  of  the  back  will  become  wedge-shaped ; 
and,  sad  to  say,  a  back  that  has 
developed  wedge-shaped  vertebrae 
—  vertebrae  that  have  kept  their 
wedge  shape  until  they  are  hard- 
ened for  life  —  can  never  hope  to 
be  straight  again. 

Bones  Enlarged  by  Work.  Cer- 
tain other  bones  may,  however,  be 
changed  by  what  they  are  com- 
pelled to  do.  To  make  them  rougher  and  larger  you  must 
work  the  muscles  which  are  fastened  to  these  bones ;  work 
them  hard ;  be  persistent,  and  the  result  will  come. 


VERTEBRA  SEEN 

FROM   THE 

SIDE 


WEDGE-SHAPED  VERTEBR/E 
Pre  '.sure  was  too  often  on  the  same  side 


37 


38          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

In  studying  human  skeletons  it  is  not  difficult  to 
point  out  the  bones  of  such  persons  as  did  vigorous 
muscular  work,  by  their  heavier  and  rougher  character, 
while  the  thin  walls  and  fragile  internal  substance  of 
other  bones  show  that  the  muscles  that  moved  them 
were  paralyzed  or  wholly  useless  during  life. 


BLOCKS  SHOWING  HOW  THE  VERTEBRAE  ARE  HELD  TOGETHER 
BY  LIGAMENTS  AND  MUSCLES 

/,  ligament ;  m,  muscle 

Evidently,  then,  active  exercise  leaves  its  mark  even 
on  the  bony  part  of  the  body.  Thus,  without  making 
any  close  examination  of  our  own  separate  bones,  we 
may  know,  by  the  exercise  we  give  them,  what  their 
prospects  are  year  by  year. 

The  Foot  under  Pressure.  Nor  are  vertebrae  the  only 
bones  to  suffer  under  pressure.  Think  of  the  bondage 
of  the-  feet,  both  in  China  and  in  other  lands. 


BONES  — THE  FRAMEWORK  OF  THE  BODY 


39 


As  I  looked  at  the  small,  deformed  feet  of  our  friend, 
the  Chinese  lady,  I  knew  what  had  happened  to  the 
bones  that  made  up  the  bulk  of  the  huge  ankle  above 
the  shoe.  No  one  saw  this  ankle.  All  we  saw  was 


CHINESE  SHOES  Two  AND  A  HALF  INCHES  LONG 
The  huge  ankle  shows  how  deformed  the  foot  really  is 

the  dainty,  handmade  shoe,  two  and  a  half  inches  long, 
embroidered  in  silk  of  lovely  shades,  and  made  of  cloth 
and  silk  with  a  leather  sole.  But  we  knew  that  within 
those  shoes  the  toes  were  drawn  in  under  the  foot,  the 
heel  drawn  forward  to  meet  them.  We  knew  that  from 
early  childhood  those  feet  had  been  held  in  bondage 


40          PHYSIOLOGY,  HYGIENE,  AND   SANITATION 

by  bandages,  that  muscles  and  tendons  had  been  kept 
from  growing,  and  that  bones  had  taken  strange  new 
shapes  of  deformity.  Fortunately  for  children  in  China, 


THE  BONES  OF  THE  FOOT 


the  government   now  forbids    foot-binding.     And    what 
about  uncomfortable  shoes  for  ourselves  ? 

The  Bones  of  the  Foot.    When  you  see  your  own  bare 
foot  to-night,  compare  its  natural  shape  with  the  shape 


BONES  AND  LIGAMENTS  OF  THE  FOOT  AND  ANKLE 

of  fashionable  shoes.   Then  consider  the  following  facts 
and  decide  what  the  sensible  course  of  action  is: 

1.  Each  foot  is  made  up  of  twenty-six  small  bones. 

2.  These    bones    are    joined    to    each    other   by 
ligaments  and  muscles. 


BONES— THE  FRAMEWORK  OF  THE  BODY 


3.  If  the  arch  of  the  foot  is  flattened,  health  is 
apt  to  suffer.  Indeed,  it  is  so  serious  a  matter  to 
be  flat-footed  that  men  with  this  handicap  are 
refused  admittance  to  the 
United  States  army.  Test  the 
condition  of  the  arch  of  your 
own  foot  by  dipping  the  bare 
sole  lightly  in  water,  then  press- 
ing it  on  blotting  paper.  The 
imprint  made  will  show  the  flat 
or  the  arched  instep.  Those 
who  stand  still  for  hours  every 
day  should  save  the  arch  by 
resting  the  weight  of  the  body 
first  on  one  foot,  then  on  the 
other.  If  you  have  any  tendency  to  flat  feet,  help 
yourself  by  standing  with  toes  turned  inwards  and, 
while  in  this  position,  rising  as  high  as  you  can  on 


A  B 

FOOTPRINTS 

A,  an  arched  foot ;  B,  a 

flat  foot 
(After  Schmidt) 


A  WOMAN'S  FOOT  DEFORMED  BY  FASHIONABLE  SHOES 
(After  Schmidt) 

your  toes.  Do  this  one  hundred  times  twice  a  day, 
or  rise  and  fall  on  the  toes  until  the  muscles  are 
tired.  The  results  will  be  satisfactory. 


42          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

4.  No  foot  can  exercise  itself  easily  unless  each 
muscle,  bone,  and  ligament  is  allowed  to  move  with 
freedom. 

Rules  for  Foot  Hygiene.  The  following  are  rules  for 
foot  hygiene : 

1.  Wear  shoes  with  soles  as  broad  as  your  foot 
is  when  you  stand  with  no  shoe  on. 

2.  Do  not  lace  shoes  so  snugly  about  the  ankle 
that  the  pressure  will  interfere  with  the  circulation 
of  blood.    Cold  feet  often  come  from  tight  shoes, 
tightly  laced. 

3.  Let  the  heels  of  your  shoes  be  broad  and  low. 

4.  Never  wear  tight  garters.   They  interfere  with 
the   movement    of    the    blood    through   the    blood 
vessels.    Wear  side  garters.    They  do  not  bind  the 
blood  vessels. 

5.  Remember  that   tan  shoes  are   rather   better 
than  black  shoes  for  summer  wear,  because  they 
do  not  keep  the  feet  so  warm. 

6.  Keep  the  feet  dry  and  warm,  but  if  possible 
avoid  overheating  them. 

7.  Be  sure  that  your  shoes  are  large  enough  to 
give  your  toes  as  well  as  your  ankle  a  chance  to 
move  and  to  be  useful  when  you  walk. 

Joints  and  their  Ligaments.  And  what  can  be  said 
about  joints,  the  movable  meeting  place  of  the  bones? 
By  every  twist  that  you  can  make,  try  to  decide  where 


BONES  — THE  FRAMEWORK  OF  THE  BODY 


43 


your  joints  are  and  how  each  works.  You  will  find 
that  some  work  back  and  forth  like  a  hinge,  while 
others  have  the  power  to  move  back  and  forth  and 
sidewise  too.  The  different  kinds  of  movement  are 


ABC 

THE  SHAPE  OF  THE  FOOT  AND  THE  SHAPE  OF  THE  SHOE 

Dotted  lines  show  the  natural  shape  of  the  foot ;  solid  lines  show  the  sole  of  the 
shoe.  A,  correct  shape ;  B,  the  large  toe  is  drawn  in  too  far ;  C,  the  shoe  is  too 
narrow.  If  you  wish  a  comfortable  and  a  well-shaped  shoe,  get  one  that  is 
wide  enough,  but  longer  than  you  need.  This  will  give  you  the  effect  of  having 

a  slender  foot 

the  result  of  different  kinds  of  joints.  Each  is  needed 
in  its  particular  place. 

The  Hinge  Joint.  Begin  with  the  hinge  joint  where 
your  skull  is  joined  to  the  upper  end  bone  of  the  spine. 
This  allows  you  to  bend  your  head  up  and  down,  and 


44 


PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


nothing  more.    But  just  below,  between  the  next  two 
bones,  is  a  joint  of  another  sort.    This  allows  you  to  turn 

your  head  from  side  to  side.  Thanks 

to  the  two  joints  acting  as  one,  you 

can  move  your  head  in  any  direction. 

Elbow  and  knee,  fingers  and  toes  — 

all  act  on  the  plan  of  the  hinge.   Test 

them  for  yourself. 
A  Ball-and-Socket 

Joint.     Whirl    your 

arm       round      and 

round     and     know 

that  you  are  using 

the    most    movable 

joint    in   the   entire 

body.  It  is  a  so-called  ball-and-socket 
joint.  The  hip  is  supplied  with  another 
of  much  the  same  kind.  Here  the  socket 
(in  the  pelvic,  or  hip,  bone)  is  shaped 
like  a  cup,  and  within  it  is  the  round 
head  of  the  femur,  .or  thigh  bone. 

When  we  think  of  the  work  which 
the  hip  and  the  knee  have  to  do  for  us, 
and  of  the  strain  we  are  ready  to  put 
on  them  at  any  moment,  we  under- 
stand why  the  hip  and  knee  joints  should  be  among 
the  firmest  and  the  strongest  parts  of  the  whole  body. 


CUT    THROUGH     THE 

HINGE  JOINT  OF  THE 

ELBOW 


BONES  AND  JOINTS 
OF  THE  LEG 


BONES  — THE  FRAMEWORK  OF  THE  BODY 


45 


Ligaments  help  make  the  joints.  These  bands  of  tissue 
are  firm  and  white  and  tough,  like  tendons.  Like  ten- 
dons, too,  they  are  slow  to  heal  when  torn.  But  they  have 
nothing  to  do  with  muscles.  Instead,  they  fasten  bones 
to  each  other,  while  tendons  fasten  muscles  to  bones. 

The  knee  is  a  won- 
derful structure  of 
bones  and  ligaments. 
It  is  a  great  hinge 
joint  supplied  with 
ligaments  which  allow 
it  to  bend  one  way, 
but  which  absolutely 
forbid  any  bending  in 
the  opposite  direction. 
If  it  were  not  for  liga- 
ments which  hold  the 
bones  together  in  a 
definite  relation,  our 
knees  would  bend  backwards  and  forwards  with  equal 
ease,  and  walking  would  be  forever  out  of  the  question. 

Two  kinds  of  joints  are  thus  seen  to  be  most  promi- 
nent in  the  body  of  man:  (i)  hinge;  (2)  ball-and-socket. 

The  Synovial  Fluid.  The  ends  of  bones  which  form 
joints  are  covered  with  smooth  and  shiny  cartilage,  or 
gristle,  to  which  ligaments  are  fastened.  Also,  within 
the  joint  itself,  there  is  a  small,  delicate  bag,  holding  a 


HIP  JOINT  DRAWN  OPEN 

Notice  the  ligament  which  holds  the  ball  in 
its  socket 


46 


PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


few  drops  of  slippery  liquid  —  synovial  fluid.   This  fluid 

lubricates  the  joints  and  helps  their  smooth  movement. 

We  have  now  learned  that  the  ends  of  our  bones  are 

shaped  to  meet  each  other;  that  they  are  carefully  fitted 

together ;  that  tough  liga- 
ments hold  the  one  to 
the  other;  and  that  mus- 
cles end  in  tendons  which 
draw  the  bones  in  such 
directions  as  the  joints 
allow.  But  bones  move 
only  when  the  heart  beats. 
We  study  this  subject  next. 

QUESTIONS 

1.  How  do  bones  help  mus- 
cles ?  2.  How  do  muscles  and 
tendons  help  bones  ?  3.  Describe 
the  outside  and  the  inside  of  a 
fresh  bone.  4.  What  does  a 
magnifying  glass  show  about  it  ? 
5.  What  can  a  chemist  do  to 
bone  ?  6.  What  can  a  cook  do 
with  a  bone  ?  7.  What  two  im- 
portant substances  form  bone  ?  8.  Why  do  aged  people  need  to  be  more 
careful  than  children  ?  9.  Describe  the  different  shapes  bones  may  have 
and  give  the  number  of  bones  in  the  human  body.  10.  What  is  a  vertebra  ? 
11.  How  many  vertebrae  are  there?  12.  How  are  they  held  together? 
13.  What  lies  between  the  vertebras  to  prevent  jarring  ?  14.  Explain  how 
vertebras  may  become  wedge  shaped,  and  tell  what  harm  results. 


THE  BACK  OF  THE  KNEE  JOINT 

Notice  the  ligaments  that  hold  the 
bones  together 


BONES  — THE  FRAMEWORK  OF  THE  BODY    47 

15.  How  many  bones  are  there  in  the  foot?  16.  How  are  they 
joined  together?  17.  Which  is  more  desirable,  the  flat  or  the  arched 
instep  ?  18.  How  can  you  decide  which  kind  you  have  ?  19.  If  you 
have  a  tendency  to  flat  feet,  how  can  you  help  save  the  arch  ?  20.  Why 
should  the  feet  be  uncramped  ?  31.  In  buying  shoes,  what  points  should 
be  kept  in  mind  ? 

22.  What  fastens  muscle  to  bone  ?  23.  Describe  how  muscles  help 
move  a  bone.  24.  To  what  bones  are  those  tendons  fastened  which  be- 
long to  the  muscle  which  forms  the  calf  of  the  leg  ?  25.  Is  the  contract- 
ing done  in  muscle  or  tendon  ?  26.  Describe  the  joints  which  lie  between 
the  skull  and  the  spine.  27.  Where  do  we  find  important  ball-and-socket 
joints  ?  28.  What  sort  of  joint  is  there  at  the  knee  ?  29.  What  is  the 
difference  between  a  tendon  and  a  ligament  ?  30.  Name  two  kinds 
of  joints.  31.  Where  do  you  find  examples  of  each? 


CHAPTER  IV 


THE  HEART  AT  WORK 

The  Pulse.    Let  some  one  hold  a  watch  while  you  and 
perhaps  your  friends  test  yourselves  in  various  ways. 

Stand  with  your  finger  on  your  pulse  at  the  wrist 
and  when  the  person  who  holds  the  watch  says,  "Get 

ready  —  begin,"  let  each  one 
start  to  count  the  regular 
throb  of  the  pulse  which 
he  feels  under  his  fingen 
Let  him  keep  on  counting 
until,  at  the  end  of  one 
minute,  the  timekeeper  says5 
"  Stop."  You  will  then  have 
your  count. 

If  you  are  not  excited,  if 
you  have  not  been  exercis- 

ing hard  beforehand,  if  you 
haye  mac[e  nQ  mistake  in 

your  counting,  the  number  of  beats  which  you  feel  will 
show  what  your  regular,  everyday  pulse  beat  is.  You 
have  secured  your  standard  for  the  standing  position. 

You  are  ready  for  the  next  test. 

48 


COUNTING  THE  PULSE  BEAT 


THE  HEART  AT  WORK 


49 


Stand  perfectly  still  and,  while  the  timekeeper  fol- 
lows the  time  again,  open  and  shut  your  hand  as  fast 
and  as  hard  as  you  can  for  an  entire  minute.  Then 
once  more  count  your  pulse.  You  may  find  that  it  has 
gained  a  trifle  in  the  number  of  beats.  This  will  depend 
on  the  vigor  with  which  you 
have  worked  the  muscles  of 
your  hand.  But  the  muscles 
there  are  small,  and  you 
will  not  get  much  result  in 
the  way  of  a  more  rapid  beat. 

Turn,  therefore,  to  the  leg 
muscles.  Use  them  vigor- 
ously. Run  up  one  flight  of 
stairs  and  back,  and  at  once 
count  the  pulse  again.  You 
will  find  a  marked  change. 
From  eighty  or  over  at  the 
start,  you  have  probably  in- 
creased the  count  to  one 
hundred  and  twenty  or  more. 

The  Pulse  Beat  and  the  Heart  Beat.  In  addition  to  the 
above  tests  make  one  more.  While  the  fingers  of  your 
left  hand  are  feeling  the  pulse  in  your  right  wrist,  place 
your  right  hand  over  your  heart.  You  will  discover  that 
the  pulse  beat  and  the  heart  beat  occur  at  the  same  in- 
stant. And  now,  if  you  were  not  uncomfortably  out  of 


HE  COUNTS  BOTH  PULSE  BEAT 
AND  HEART  BEAT 


50          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

breath  after  the  run  up  one  flight,  try  two  flights  and 
notice  that  the  number  of  beats  has  increased  both  at 
the  wrist  and  at  -the  heart.  You  have  proved  for  your- 
self that  the  pulse  beat  may  be  depended  on  to  show 
the  rate  of  the  heart  beat. 

The  Effect  of  Exercise  on  the  Heart.  The  following 
table  shows  what  such  exercise  did  for  a  small  class 
of  children  in  a  New  York  school.  The  letters  of  the 
alphabet  stand  for  the  names  of  the  children. 

TESTS  SHOWING  EFFECTS  OF  EXERCISE  ON  THE 
HEART  BEAT  PER  MINUTE 


A  .    .     .    . 

NORMAL 
PULSE 

8c 

AFTER  SHORT, 
QUICK  RUN 

T  -J  Q 

B  .    .    .     . 

.  8^ 

.        AJ^ 

I  ZL2 

C  .    .     .    . 

.    71 

113 

D  .     .     .     . 

.  8c 

A  Ao 
or 

E            .    * 

gr 

V  j 
I  I  "Z 

F  .    .    .    . 

.     *    .     .88 

•    A  16 
1  20 

G  . 

.  8* 

CK 

Each  child  was  tested  again  within  a  minute  after 
the  run,  and  already  the  pulse  was  found  to  be  beat- 
ing more  slowly.  This  rapid  return  to  the  normal  beat 
is  the  sign  of  a  healthy  heart. 

Test  yourself  in  other  ways.  Count  your  pulse  when 
you  get  up  rested  in  the  morning  and  when  you  go 
to  bed  tired  at  night.  Count  it  before  and  after  your 
cold  bath  in  the  morning.  Count  it  before  and  after 


THE  HEART  AT  WORK 


any  kind  of  exercise  that  interests  you.  For  example, 
run  to  school  one  morning,  walk  another  morning,  and 
compare  the  results  of  both  with  your  standard.  Com- 
pare the  number  of  beats  of  the  heart  that  has  done 
hard  work  with  those  of 
the  heart  that  has  done 
light  work,  and  see  what 
gives  your  heart  the 
most  exercise.  Through 
all  this  you  learn  what 
the  power  of  your  own 
heart  is. 

Already  you  know  that 
exercise  makes  the  heart 
beat  faster,  and  that  the 
larger  the  muscles  are 
and  the  harder  the  work 
they  do  —  running,  for 
example  —  the  more  ex- 
ercise will  the  heart  have. 
You  have  also  learned 
that  the  pulse  may  al- 
ways be  trusted  to  tell 
important  facts  about  the  action  of  the  heart. 

What  the  Pulse  Beat  Proves.  It  is  for  this  last  reason 
that  a  doctor  feels  the  pulse  of  his  patient.  By  the 
regular  or  the  irregular  beat  of  that  pulse,  by  the  way 


THE  HEART  AND  ITS  GREAT 
BLOOD  VESSELS 

We  are  well  or  ill,  we  live  or  die,  by  the 
work  it  does  or  fails  to  do 


52          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

it  hurries  or  by  the  way  it  drags,  he  is  guided  in  his 
judgment  as  to  what  the  condition  of  the  patient  is 
and  what  ought  to  be  done  to  help  him.  The  heart, 
indeed,  is  one  of  the  vital  centers  of  our  activities. 
We  are  well  or  ill,  we  live  or  die,  through  the  work 
which  it  does  or  fails  to  do.  Yet  ignorant  persons  often 
give  it  either  too  much  or  too  little  exercise.  Many  frail 
women  fear  to  take  exercise  lest  they  overtax  the  heart, 
while  bicycle  riders,  and  others  who  exert  themselves 
beyond  reason,  often  overtax  the  heart  until  it  is  injured 
for  life.  This  is  also  true  of  boys  who  run  long  or  hard 
races  before  their  hearts  have  been  trained  for  such 
violent  exercise. 

The  Heart  Muscle.  It  seems  that  the  heart  is  a  strong 
hollow  muscle  about  as  large  as  the  fist  of  the  one 
for  whom  it  works,  and  that  even  when  it  is  not 
overtaxed  it  does  more  work  than  any  other  muscle 
in  the  body.  It  lies  under  the  ribs,  between  the  two 
halves  of  the  lungs,  and  keeps  up  its  beating  from  birth 
to  death.  Even  though  it  is  so  constantly  active,  still, 
like  every  other  muscle,  exercise  gives  it  strength,  while 
lack  of  exercise  leaves  it  weak. 

In  training  this  important  muscle  let  us  remember 
that  most  human  beings  have  sound  hearts  that  need 
to  be  treated  in  a  reasonable  way. 

Overtaxing  the  Heart.  A  neighbor  of  ours  had  taken 
no  special  exercise  all  winter,  but  when  spring  came 


THE  HEART  AT  WORK  53 

he  began  abruptly  by  playing  one  set  of  tennis  after 
another  without  resting.  The  result  was  that  for  many 
days  and  nights  his  heart  kept  up  a  rapid  beating.  For 
three  weeks,  indeed,  it  refused  to  come  down  to  normal, 
and  during  this  time  the  man  dared  take  no  exercise 
whatever.  He  knew  it 
would  be  unsafe. 

If  he  had  been  careful 
to  begin  his  tennis-playing 
gradually,  increasing  the 
amount  from  day  to  day, 
he  would  have  done  better 
work,  would  have  spared 
his  heart  the  overstrain,  and 
would  have  saved  himself 
weeks  of  weariness. 

Training  Heart  and  Mus- 
cles Together.  Watch  those 

who     race     to    Catch     a    Car.  AT  THE  CRITICAL  MOMENT 

By  the  way  they  breathe  you  may  know  what  the  heart 
is  doing.  You  will  also  be  able  to  tell  which  of  the 
running  men  and  women  have  trained  their  hearts  for 
sudden  sprints  of  violent  work,  and  which  are  pressing 
untrained  hearts  into  unusual  service.  College  students 
often  run  by  the  mile  across  the  town  and  out  into  the 
country.  They  are  training  not  only  the  many  muscles 
of  their  legs  but  also  the  one  muscle  of  the  heart  and 


54          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

their  breathing  apparatus  as  well.  They  wish  to  train 
their  leg  muscles,  while  at  the  same  time  'they  secure 
for  themselves  hearts  and  lungs  that  will  help  each 
other  and  be  useful  as  long  as  their  legs  are  able  to 
keep  up  the  running. 

A  doctor  whom  I  know  speaks  of  a  man  whom  he 
himself  trained.  He  says: 

When  I  took  charge  of  him  the  man  could  not  run  as  far  as  from 
here  to  the  door  without  fainting.  He  simply  had  a  muscularly  weak 
heart,  excited  by  nervous  shock  and  overwork,  worry,  deficient  nutri- 
tion, and  lack  of  sleep.  I  first  discovered  that  there  was  no  organic 
disease.  Nothing  but  plain  building  up  of  muscle  was  needed.  Then 
I  went  to  work  and  started  to  build  up  that  muscle.  I  would  have  him 
run  a  few  steps  and  then  lie  down  three  minutes,  then  run  a  few  steps 
more  and  lie  down.  I  stood  by,  keeping  track  of  his  heart,  not  allowing 
him  to  do  enough  work  to  send  it  above  one  hundred  and  not  letting 
him  run  again  until  it  got  back  to  normal.  I  kept  him  at  it  half  an 
hour  three  times  a  day,  from  day  to  day  increasing  the  doses ;  that  is, 
I  stuck  to  the  medicine,  but  I  gave  very  small  doses,  —  doses  suited 
to  the  strength  of  heart  he  then  had.  In  three  months  that  man  could 
run  eight  miles  an  hour  with  great  ease  and  comfort.  Since  then  he 
has  not  known  that  he  has  a  heart. 

Overstretching  the  Heart.  This  doctor  also  speaks  of 
a  friend  of  his  who  ran  up  eight  flights  of  stairs  be- 
cause of  a  fire,  and  so  overstrained  his  heart  that  it 
has  never  been  right  since. 

This  shows  that  when  the  heart  has  done  what  it 
comfortably  can,  and  then  has'  to  do  still  more  work 
and  keep  it  up,  it  stretches  too  much  for  its  own  good. 


THE  HEART  AT  WORK  55 

And  worse  still,  if  stretched  badly  enough,  it  stays 
stretched.  This  is  part  of  the  trouble  with  the  over- 
worked heart  of  the  bicycle  rider.  Athletic  trainers 
understand  these  facts  thoroughly.  It  is  therefore  as 
much  for  the  sake  of  the  muscle  of  the  heart  as  for 
the  benefit  of  leg  muscles  that  they  insist  that  only 
those  who  have  been  trained  for  the  contests  shall  be 
allowed  to  compete  in  athletic  games.  Otherwise  the 
untrained  person  might  faint  in  the  midst  of  the  sport, 
harming  himself  and  frightening  everybody. 

The  safe  rule  is  to  give  the  heart  all  the  exercise 
it  can  comfortably  take  at  one  time,  and  to  increase 
the  amount  as  fast  as  its  power  increases. 

As  a  rule,  the  actual  size  of  the  normal  heart  is  large 
or  small  according  to  the  work  it  has  had  to  do.  Animals 
kept  in  cages  and  captivity  have  been  examined  after 
death,  and  their  hearts  have  been  seen  to  be  smaller 
than  the  average  heart  of  wild  animals  of  the  same  kind. 
In  proportion  to  his  size,  the  heart  of  a  stag  is  about 
twice  as  large  as  that  of  a  pig.  The  reason  is  plain. 
The  stag  lives  by  exercise  which  makes  the  heart 
work;  the  pig,  except  in  the  wild  state  or  in  pasture, 
seldom  takes  any  unusual  exercise. 

Heart  Development.  Provided  one  does  not  undertake 
too  much,  nothing  is  better  for  heart  development  than 
exercise  which  calls  for  endurance.  A  quick  run  for  a 
minute,  or  a  brisk  jog  trot  lasting  five  minutes,  is  as 


56          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

good  as  anything  that  can  be  devised.  Run  a  little  as 
you  go  to  school  in  the  morning,  then  walk  a  little. 
Run  only  as  much  as  you  can  quickly  recover  from.  By 
your  pulse  beat  and  by  the  way  you  keep  your  breath 
or  lose  it,  you  will  know  what  you  may  do.  Begin  with 
little  exercise,  for  you  are  going  to  make  steady  gain 
whatever  your  starting  point  is,  and  you  gain  most  by 
going  moderately  at  first. 

Throughout  his  entire  life  the  person  who  has  a 
well-developed  heart  will  also  have  more  vigor,  more 
power  to  endure,  more  courage  than  he  otherwise  would 
have.  The  result  is  worth  working  for. 

Harvey's  Discovery.  This  we  all  know  now,  but  three 
hundred  years  ago  even  learned  men  were  ignorant 
both  about  the  heart  and  about  its  activities.  Then 
came  Harvey's  great  discovery.  In  1616  we  find 
William  Harvey,  an  English  physician,  lecturing  in 
London.  He  was  only  thirty-eight  years  old,  and  already 
his  medical  reputation  was  very  great.  When  he  died, 
at  the  age  of  seventy-nine,  he  had  changed  certain 
beliefs  of  the  human  race.  Nor  did  this  come  about  by 
accident.  During  his  active  life,  whenever  he  had  the 
opportunity  for  it,  —  whether  with  men  or  with  animals, 
whether  with  those  who  were  well  or  ill,  alive  or  dead,  — 
he  studied  the  body  and  gave  special  attention  to  the 
action  of  the  heart  and  to  any  connection  which  it 
might  have  with  the  blood  supply. 


THE  HEART  AT  WORK  57 

Arterial  and  Venous  Blood.  In  the  case  of  wounded 
animals,  at  different  times  he  laid  his  hand  on  the  heart 
and  noticed  that  with  each  throb  the  blood  left  the 
wound  with  a  spurt,  and  he  saw  that  blood  which 
spurted  in  jets  from  a  wound  was  always  of  the  bright- 
red  kind.  This  is  now  known  as  arterial  blood. 

Then  too  he  observed  wounds  that  bled  in  a  dif- 
ferent way.  The  blood  simply  poured  out  in  a  quiet, 
dark-purplish  stream,  and  there  was  no  sudden  increase 
of  flow  with  the  heart  beat.  This  is  venous  blood.  He 
found  that  the  same  was  true  for  wounds  in  man  and 
beast  alike  —  that  bright  blood  came  in  jets,  while  dark 
blood  came  in  a  quiet  stream.  He  saw  too  that  when- 
ever the  heart  beat  slowly  the  pulse  at  the  wrist  was 
slow  too. 

These  important  observations,  added  to  many  experi- 
ments which  he  himself  made,  drew  Harvey's  thoughts 
more  and  more  to  questions  about  circulation.  It  then 
occurred  to  him  that  the  heart  might  be  a  special 
machine  for  pumping  bright-colored  blood  out  into  the 
arteries,  and  the  thought  of  such  a  possibility  was  excit- 
ing even  to  himself,  for  no  one  had  suspected  this  before. 

Arteries  and  Veins.  Through  yet  other  experiments 
and  constant  thought  on  the  subject,  his  surmises  grad- 
ually changed  to  convictions.  He  became  very  sure  that 
every  pulse  beat  in  the  artery  at  the  wrist  meant  that 
the  heart  had  pumped  a  fresh  supply  of  blood  into  the 


58          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

large  artery  —  the  aorta  —  which  is  joined  directly  to  it, 
and  that  the  elastic  tubes  had  expanded  throughout  their 
entire  length  to  make  room  for  the  blood.  He  knew,  as 
we  do,  that  the  largest  arteries  are  buried  deeper  in  the 
body  than  the  veins,  and  that  only  at  certain  spots  do 
they  come  near  enough  to  the  surface  to  allow  us  to  feel 
the  effect  of  the  heart  beat.  He  noticed  that  there  is 
never  any  throb  in  a  vein,  and  this  strengthened  his 
conviction  that  no  vein  ever  receives  blood  directly 
from  the  throbbing  heart. 

The  Work  of  the  Heart.  By  traveling  the  road  which 
he  took,  we  have  come  upon  Harvey's  first  great 
discovery :  the  heart  pumps  blood  into  the  arteries. 

The  scientific  world  was  greatly  excited  over  this 
announcement.  But  Harvey  himself  went  quietly  on 
with  his  investigations.  He  used  his  own  methods  of 
measurement,  which  are  different  from  ours.  But  the 
amount  of  blood  in  the  human  body  was  the  same 
then  as  now,  and  it  was  this  blood  supply  that  Harvey 
studied  and  that  we  also  are  studying.  He  saw  that  the 
heart  pumps  by  contracting  and  expanding;  that  the 
average  human  body  holds  about  six  quarts  of  blood ; 
that  the  heart  sends  about  half  a  tumblerful  of  blood 
into  the  aorta  every  time  it  contracts;  and  that,  since 
the  heart  beats  about  seventy  times  a  minute,  an  enor- 
mous quantity  of  blood  must  be  squeezed  out  of  it 
during  each  half  hour. 


THE  HEART  AT  WORK 


59 


He  did  some  multiplying,  and  decided  that  if  the 
heart  sends  out  over  two  thousand  tumblerfuls  of  blood 
every  hour,  and  if  the  body  holds  no  more  than  twenty- 
four  tumblerfuls,  —  that  is,  six  quarts,  —  the  enormous 
supply  must  be  explained  somehow.  We  of  course  know 
that  the  same  blood  is  being  pumped  over  and  over 
again,  and  that  this  explains  the  quantity.  But  Harvey 
did  not  know  this.  He 
asked  where  it  all  came 
from. 

One  sign  after  an- 
other led  him  to  sus- 
pect that  the  veins 
might  supply  the  ex- 
planation. He  there-  POCKET  VALVES  IN  THE  VEINS 
fore  tested  both  veins 
and  arteries,  as  we  our- 
selves may  do. 

The  Use  of  Valves  in  the  Veins.  Draw  up  your  sleeve, 
swing  your  arm  round  your  head  once  or  twice,  let  it  hang 
by  your  side  for  a  minute,  and  you  will  notice  that  some 
of  the  blood  vessels  appear  as  dark  lines  under  the  skin. 
Stroke  these  lines  down  towards  the  wrist.  They  are 
veins,  and  the  little  bunches  which  stand  out  show 
where  the  valves  have  caught  the  blood.  These  valves 
are  on  the  inside  lining  of  every  vein,  and  they  always 
open  towards  the  heart.  When  blood  in  a  vein  flows 


A 


A  shows  a  vein  slit  lengthwise  and  laid  open ; 

B   shows    a    vein    cut    through    lengthwise ; 

C  shows  how  a  vein  looks  from  the  outside 

when  its  valves  are  filled  with  blood 


60          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

towards  the  heart,  the  valves  lie  flat  and  smooth  against 
the  lining,  and  you  would  not  suspect  their  presence. 
But  try  to  drive  that  blood  in  the  vein  away  from  the 
heart,  and  quickly  every  valve  is  lifted  so  that  it  stands 

out  like  a  little  pouch  and  blocks 
the  passage  of  the  blood  back- 
wards. The  structure  of  the 
veins,  therefore,  helped  Harvey 
on  towards  his  next  discovery. 

Experiments  with  the  Blood 
Flow.  Uncover  your  left  arm  and 
squeeze  it  with  your  right  hand, 
stroking  the  arm  hard  upward 
towards  the  elbow  to  hasten  the 
blood  out  of  the  veins.  Now,  as 
quickly  as  you  can,  tie  a  bandage 
tight  about  the  arm  just  above 
the  elbow.  Within  a  few  seconds 
notice  how  you  feel,  and  notice 
the  color  of  your  hand.  It  is 
pale  and  grows  cold. 
Arteries  are  buried  deep.  Veins  are  near  the  surface. 
Your  bandage  is  therefore  checking  the  flow  in  both 
sets  of  blood  vessels,  and  because  no  blood  can  get  into 
the  forearm,  the  color  of  it  stays  about  as  it  was  after 
you  had  tied  the  bandage.  Above  the  elbow,  however, 
you  feel  a  throbbing,  because  the  blood  in  the  arteries 


A  HANDKERCHIEF  AND  A 

STICK  TO   COMPRESS   AN 

ARTERY 

As  the  stick  is  turned  the 
bandage  is  pulled  tighter 


THE  HEART  AT  WORK 


6l 


is  held  back  by  the  dam  of  the  bandage.  Loosen  the 
bandage  a  little.  You  have  now  lifted  the  pressure 
from  the  arteries,  and  blood  hurries  towards  the  hand. 
But  the  veins  are  under  pressure  still ;  notice  what  is 
happening.  Blood  is  enter- 
ing through  the  arteries;  it 
cannot  escape  through  the 
veins  because  of  the  pressure 
of  the  bandage.  As  a  result 
the  hand  grows  red  and  swol- 
len from  its  unusual  supply. 
Release  the  bandage  entirely, 
and  in  almost  no  time  the 
veins  will  have  relieved  them- 
selves. Blood  is  once  more 
streaming  upwards. 

Such  experiments  as  these 
and  others  led  Harvey  to  his 
second  announcement.  He 
declared  to  his  astonished 
friends  that  the  heart  receives  its  entire  blood  supply  from 
the  veins. 

The  Structure  of  the  Heart.  To  complete  this  account, 
turn  to  the  heart  again  and  remember  the  following 
facts  about  it : 

i.  The  heart  is  a  powerful  muscle.    It  does  its 
work  by  contracting  and  relaxing.    When  it  relaxes, 


THE  RIGHT  AURICLE  AND 
VENTRICLE 

A,  vein  that  brings  blood  to  the  auri- 
cle ;  B,  auricle ;  C,  valves  that  are 
forced  open  by  the  blood  as  it  passes 
into  the  ventricle ;  Z>,  ventricle  ;  £, 
tube  through  which  blood  goes  to 
the  lungs  to  be  purified 


62 


PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


the  blood  pours  into  it  through  an  open  valve; 
when  it  contracts,  it  forces  about  half  a  teacup  of 
blood  at  a  time  onward  and  out  of  it  through  an- 
other open  valve.  Each  time  it  contracts,  its  apex 
touches  the  wall  of  the  chest  near  the  fifth  rib. 
This  is  what  we  feel  and  call  the  heart  beat.  After 


TWO   VIEWS   OF  THE    SAME  VENTRICLE  TO   SHOW  THE  VALVES 

On  the  left  blood  enters ;  on  the  right  the  ventricle  contracts 
and  forces  the  blood  onward 


each  of  these  beats,  the  heart  relaxes  and  rests  while 
more  blood  pours  into  it.  We  see  from  this  that 
the  heart  rests  about  half  the  time. 

2.  The  heart  is  made  up  of  two  halves,  and  the 
wall  of  muscle  between  these  separate  halves  is  so 
firmly  closed  that  after  birth,  and  after  the  heart 
is  in  good  working  order,  not  a  drop  of  blood  ever 
passes  through  it  from  one  side  to  the  other. 


THE  HEART  AT  WORK  63 

3.  Each  half  of  the  heart  has  two  divisions,  the 
smaller   called    the   auricle,   the   larger   called    the 
ventricle. 

4.  Each  auricle  and   each  ventricle  has  its  own 
opening,  its  own  tube  for  blood,  and  its  own  valves 
to  prevent  the  blood  from  running  the  wrong  way. 

5.  The  auricle  in  each  half  of  the  heart  always  re- 
ceives the  blood  and  sends  it  into  its  own  ventricle. 

6.  Each  ventricle   receives    blood   from    its  own 
auricle  and  sends  it  off  to  its  own  district  of  the 
body. 

7.  Tubes  which  carry  blood  from  the  heart  are 
called    arteries.     Tubes  which   carry  blood    to    the 
heart  are  called  veins. 

8.  The  right  side   of  the   heart   receives  impure 
blood  from  the  body  and  sends  it  to  the  lungs  to  be 
purified.    This  is  called  the  pulmonary  circulation. 
The  left    side    of   the   heart   receives   the   cleaned, 
purified    blood    from    the    lungs    and    sends    it    off 
through  a  large  artery,  the  aorta,  for  use  everywhere 
in  the  body.    This  is  called  the  systemic  circulation. 

The  Double  Work  of  the  Heart.  At  this  point  we  reach 
a  most  interesting  fact  about  the  process  of  circulation, 
yet  it  may  be  given  in  a  few  easy  words.  One  side  of 
the  heart  always  receives  blood  from  the  body  and  sends  it 
to  the  lungs ;  the  other  side  of  the  heart  always  receives 
blood  from  the  lungs  and  sends  it  through  the  body. 


D 


64          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

We  see,  then,  that  one  side  deals  with  pure  blood  alone, 
for  all  that  comes  to  it  is  fresh  from  the  lungs  and 
is  sent  onward  in  the  same  condition ;  while  the  other 

side  deals  with  impure  blood 
alone,  for  all  that  comes  to 
it  has  been  used  by  the 
body  and  in  this  condition 
goes  direct  to  the  lungs  to 
be  purified. 

Thus  the  entire  blood  sup- 
ply of  the  body,  on  each  jour- 
ney round,  passes  through 
both  sides  of  the  heart  and 
through  the  lungs  before  it 
goes  back  to  nourish  the  body. 
This  was  Harvey's  great  dis- 
covery about  the  circulation 
of  the  blood.  Even  for  him, 
however,  there  was  still  a 
mystery.  "What  becomes  of 
the  blood  between  times  ? "  he 
asked.  "  How  does  it  get  from 
the  arteries  to  the  veins  for  its 
journey  back  to  the  heart  ?  " 
Capillary  Connections.  Harvey  himself  was  not  able 
to  answer  these  questions,  for  microscopes  had  not  yet 
been  .invented,  and  nothing  but  the  microscope  can 


THE  FOUR  CAVITIES  OF  THE 
HEART 

A,  auricle  ;  B,  ventricle  ;    C,  outline 
of  the  heart ;  D,  D,  blood  vessels 

The  dark  side  receives  impure  blood 
from  the  body  and  sends  it  to  the 
lungs ;  the  light  side  receives  pure 
blood  from  the  lungs  and  sends  it 
to  the  body 


THE  HEART  AT  WORK  65 

reveal  the  close  network  of  capillary  connections  which 
carries  the  blood  across  from  arteries  to  veins  for  the 
return  trip  to  the  heart. 

The  Circulatory  System.  But  when  the  microscope 
came  with  its  revelations,  doubts  and  questions  were 
cleared  away.  Instead  of  blood  spread  about  everywhere 
among  the  muscles,  under  the  skin,  between  the  arteries 
and  the  veins,  there  was  found  to  be  no  blood  anywhere 
outside  of  the  tubes.  Moreover,  each  drop  of  blood  was 
found  to  be  a  part  of  the  ceaseless  stream  which  flows 
through  tubes  that  divide  and  subdivide  until  they  are 
too  small  for  the  unaided  eye  to  see,  and  then  unite  and 
continue  to  unite  until  they  are  again  large  enough  to 
be  seen.  This  is  well  called  the  circulatory  system,  for 
round  and  round  the  blood  goes  in  endless  circulation ; 
and  when  the  circulating  stops,  we  stop  living. 

The  following  table  shows  how  long  it  takes  blood  to 
make  the  entire  circuit  of  the  body  in  different  animals.1 

Horse 25  seconds 

Full-grown  man 23  seconds 

Child  of  fourteen 18  seconds 

Child  of  three 15  seconds 

Thus  swiftly  does  the  blood  within  us  stream  from 
the  heart  through  arteries,  capillaries,  and  veins,  back 

1  A  trained  person  pricks  some  harmless  chemical  into  a  vein  on  one  side  of 
the  body,  then  examines  blood  from  the  corresponding  vein  on  the  opposite  side 
of  the  body  until  the  same  chemical  appears  there.  By  this  he  learns  how  long 
it  takes  blood  to  make  the  circuit. 


VEINS  AND  ARTERIES 

Black  tubes  represent  veins  through  which  impure  blood  goes  to  the  right  side 

of  the  heart  from  all  parts  of  the  body ;  light-colored  tubes  represent  arteries 

through  which  pure  blood  from  the  left  side  of  the  heart  goes  to  all  parts  of  the 

body.    Notice  that  the  large  tubes  of  each  kind  lie  near  one  another 

66 


THE  HEART  AT  WORK 


67 


to  the  heart  again.  And  the  sight  of  its  progress 
through  the  tubes  must  have  thrilled  those  who  watched 
it  for  the  first  time. 

Corpuscles  in  the  Capillaries.  One  early  scientist,  who 
lived  over  two  hundred  years  ago,  looked  through  his 
crude  microscope  at 
the  tail  of  a  tadpole. 
He  had  already  dis- 
covered the  corpus- 
cles of  the  blood, 
which  we  shall  study 
soon,  and  he  saw 
these  separate  "blood 
globules,"  as  he 
called  them,  moving 
after  each  other  in 
single  file  through 
the  narrowest  of  the 
tubes.  Sometimes 
they  moved  in  faster, 
sometimes  in  slower, 
procession ;  and  sometimes  they  were  even  bent  over 
and  pressed  out  of  shape  as  they  were  forced  through 
the  narrowest  places.  He  grew  enthusiastic  over  what 
he  saw,  and  wrote  a  glowing  account  of  it. 

The  motion  of  the  blood  in  these  tadpoles  exceeds  all  the  rest  of  small 
animals  and  fish  I  have  ever  seen ;  nay  this  pleasure  has  ofttimes  been 


UNION  OF  ARTERIES  AND  VEINS 

a,  artery ;  v,  vein.    A  network  of  capillaries 
joins  them 


68          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


so  recreating  to  me  that  I  do  not  believe  that  all  the  pleasures  of  foun- 
tains and  waterworks,  either  natural  or  made  by  art,  could  have  pleased 
my  sight  so  well.  And  now  at  last  I  spied  a  small  artery,  that  notwith- 
standing it  is  so  small  that,  I  judge,  but  one  small  red  globule  of  blood 
could  pass  through  it,  ...  yet,  what  was  most  remarkable  was  to  see 
the  manifold  small  arteries  that  came  forth  from  the  gceat  one,  and  which 
were  spread  into  several  branches,  and  turning,  came  into  one  again,  and 
were  reunited,  that  at  last  they  did  pour  out  the  blood  again  into  the 

great  vein  ;  this  last  was  a  sight  that 
would  amaze  any  eye  that  was  greedy 
of  knowledge. 

From  what  we  saw,  and  from 
what  we  may  see  for  ourselves 
with  the  microscope,  we  find 
it  easy  to  understand  that  every 
gash  made  in  the  flesh  of  the 

^cdy    cuts    through    a    mesh    of 
. 

lacework  more  delicate  than 
the  finest  lace  ever  made  by  the  hand  of  man  ;  we  see 
that  each  thread  of  this  lace  is  a  tube  doing  faithful  duty 
in  carrying  blood  to  remote  regions  of  the  body  ;  we  see 
that  everywhere  there  is  blood  simply  because  every- 
where there  is  the  same  intricate  interlacing  of  these 
marvelous  tubes.  Their  name  capillary  means  "hairlike." 
Yet  the  microscope  shows  how  much  smaller  they  some- 
times are  than  any  human  hair,  however  soft  and  fine. 

By  careful  calculation  it  has  been  found  that  fifteen 
hundred  capillaries  would  have  to  be  laid  side  by  side 
to  cover  a  surface  an  inch  wide. 


CORPUSCLES  IN  THE  CAPILLARIES 
OF  A  FROG'S  FOOT 


THE  HEART  WITH  ITS  SYSTEM  OF  TUBES 

Arrows  show  the  direction  in  which  the  blood  flows.    Follow  its  course  from  the 

body  into  the  right  side  of  the  heart ;  from  there  to  the  lungs ;  thence  to  the  left 

side  of  the  heart  and  out  to  the  body  again.    Each  cluster  of  tubes  shows  in  a 

rough  way  where  some  organ  of  the  body  is  located 

69 


70          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

The  Blood  Supply.  As  a  rule,  the  amount  of  blood 
which  is  inclosed  in  the  system  of  tubes  which  includes 
heart,  arteries,  capillaries,  and  veins  is  about  one  thir- 
teenth the  weight  of  the  person.  We  may  then  calculate 
our  own  supply  of  blood  by  our  own  weight,  and  decide 
just  how  much  it  takes  to  keep  our  blood  vessels  and 
heart  as  full  as  they  need  to  be.  The  truth,  however, 
is  that  being  elastic  they  could  at  any  time  hold 
more  than  is  now  in  them ;  and  that  at  any  time  also 
they  could  get  along  very  well  with  less  than  they 
now  carry. 

In  former  times  men  sometimes  died  for  no  other  rea- 
son than  that  they  lost  so  much  blood  from  wounds  of 
one  sort  or  another  that  the  sides  of  veins  and  capil- 
laries collapsed,  and  the  heart  had  to  stop  work  because 
there  was  too  little  blood  left  in  the  body  to  be  pumped 
round.  It  was  therefore  a  great  discovery  when  men 
found  that  the  heart  is  quite  as  willing  to  pump  warm 
salt  water  out  into  arteries  and  capillaries  as  to  send 
warm  blood  to  the  same  places.  Nowadays,  therefore, 
when  a  man  is  losing  much  blood  through  an  operation 
or  through  an  accidental  wound,  a  surgeon,  working  as 
fast  as  he  can,  pumps  salt  water  into  the  veins  to  replace 
the  blood.  This  water  is  carried  on  round  the  circuit  as 
swiftly  as  if  it  were  the  richest  blood,  the  pumping  of 
the  heart  continues,  and  a  life  is  saved.  It  keeps  the 
veins. filled  and  the  heart  in  action  for  a  season,  while 


THE  HEART  AT  WORK  71 

the  proper  sort  of  blood  is  being  manufactured  by  the 
body  itself. 

Exercise  and  the  Blood  Supply.  In  a  way  we  might 
suppose  that  the  blood  of  the  body  is  spread  out  in  equal 
quantities  everywhere,  being  regulated  by  the  size  of  the 
tubes  which  carry  it  about.  The  truth  is,  however,  that 
exercise  regulates  the  amount  of  blood  which  goes  here  or 
there ;  that  is,  what  we  do  always  settles  the  question  as 
to  where  the  blood  shall  go.  For  the  normal  healthy  per- 
son this  law  never  varies.  It  may  be  stated  in  a  few 
words :  that  part  of  the  body  which  is  exercised  the  most 
gets  the  most  blood ;  that  part  which  is  exercised  the  least 
gets  the  least  blood. 

The  sixth  chapter  shows  what  it  means  to  the  body 
when  this  law  is  remembered  or  forgotten,  and  what  the 
nature  of  the  blood  is,  that  it  should  be  so  greatly 
needed  here  and  there.  But  before  taking  up  that  sub- 
ject, we  turn  to  the  study  of  heart  action  and  nicotine* 

QUESTIONS 

1.  How  may  you  get  the  standard  of  your  heart  beat?  2.  What 
shows  the  rate  of  heart  beat,  and  how  can  you  increase  that  rate  ? 

3.  Which  increases  heart  beat  more,  exercise  of  large  or  of  small  muscles? 

4.  Why  does  a  doctor  feel  the  pulse  of  his  patient?    5.  Give  two  op- 
posite mistakes  often  made  in  exercising  the  heart.     6.  Describe  the 
heart  —  its    structure,    position,    and    size.      7.  When    does   it   work? 

8.  How  may  the  heart  of  a  tennis  player  show  that  it  is  overtaxed  ? 

9.  How  should  one  begin  tennis-playing  in  the  spring?    10..  Mention 


72          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

some  way  by  which  muscles,  heart,  and  breathing  apparatus  can  all  be 
trained  at  the  same  time.  11.  What  advantage  is  there  in  having  a 
well-trained  heart  ? 

12.  Who  was  William  Harvey?  13.  What  did  he  notice  about  the 
flow  of  blood  from  different  wounds?  14.  What  was  Harvey's  first 
great  discovery  ?  15.  Give  some  facts  that  led  him  to  this  discovery. 
16.  How  many  quarts  of  blood  are  there  in  the  body  ?  17.  How  much 
blood  does  the  heart  send  out  each  time  it  contracts  ?  18.  How  often 
does  it  contract  each  minute  ?  19.  What  are  the  pockets  in  the  veins  ? 
20.  Which  are  deeper  in  the  body,  arteries  or  veins?  21.  WThat  does 
the  experiment  with  the  bandage  above  the  elbow  prove?  22.  What 
was  Harvey's  second  discovery?  23.  What  can  you  say  about  the 
two  halves  of  the  heart  ?  24.  What  is  the  work  of  the  auricle  ?  the 
ventricle  ?  the  arteries  ?  the  veins  ?  25.  What  is  the  aorta  ?  26.  Which 
side  of  the  heart  receives  impure  blood  from  the  body  and  sends  it  to 
the  lungs  to  be  purified?  27.  Which  side  receives  pure  blood  from  the 
lungs  and  sends  it  to  the  whole  body  to  be  used  ? 

28.  How  long  does  it  take  blood  to  make  the  circuit  of  the  body  for 
a  man  ?  for  a  child  of  fourteen  ?  29.  Describe  the  circuit  of  the  blood 
from  the  veins  back  to  the  veins.  30.  How  does  the  blood  get  from 
the  arteries  to  the  veins  for  its  return  journey  to  the  heart?  31.  When 
you  cut  yourself  and  blood  flows,  what  have  you  actually  done? 
32.  What  does  capillary  mean?  33.  What  can  you  say  about  the 
amount  of  blood  which  the  blood  vessels  may  hold  ?  34.  In  what 
way  is  warm  salt  water  sometimes  useful  in  blood  vessels?  35.  What 
connection  is  there  between  exercise  and  the  amount  of  blood  sent 
to  different  parts  of  the  body  ?  36.  Give  this  law  of  exercise. 


CHAPTER  V 

NICOTINE  AND  THE  SPHYGMOGRAPH 

Tests  with  the  Sphygmograph.  In  some  tests  which 
he  was  making,  Dr.  McKeever1  enlisted  the  help  of  over 
one  hundred  boys.  Their  ages  ranged  from  twelve  to 
twenty  years,  and  they  all  smoked.  Indeed  it  was  just 
because  they  smoked  that  Dr.  McKeever  was  making 
his  tests.  He  wished  to  see  for  himself  what  tobacco 
does  for  boys.  If  it  helps  them  either  in  body  or  in 
mind,  he  intended  to  pass  the  fact  on  for  the  benefit 
of  other  boys. 

In  carrying  on  his  investigations  Dr.  McKeever  used 
the  sphygmograph.  This  machine  has  a  clockwork  con- 
trivance which  moves  a  strip  of  smoked  paper  on  which 
a  needle  records  the  heart  beat.  It  is  fastened  to  the 
wrist  directly  over  the  artery  which  passes  that  way, 
and  as  the  artery  throbs  with  the  beating  of  the  heart, 
the  needle  of  the  sphygmograph  traces  its  way  across 
the  smoked  paper  and  leaves  its  scientifically  exact 
record  there,  in  black  and  white.  The  illustration  on 
the  next  page  shows  the  making  of  a  record. 

1  Dr.  William  A.  McKeever,  Professor  of  Child  Welfare,  The  University 
of  Kansas. 

73 


74 


PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


The  boys  were  interested  in  the  way  the  machine 
worked  and  in  what  it  told  about  their  heart  action 
before  and  after  smoking. 

General  Effects  of  Smoking.  The  records  were  taken  at 
different  times  during  the  year,  and  each  was  slightly 
different  from  all  the  others,  just  as  the  handwriting 


THE  SPHYGMOGRAPH  ON  A  WRIST,  AND  THE  RECORD  IT  is  MAKING 

of  one  person  always  differs  from  that  of  another.  On 
the  whole,  however,  the  various  reports  of  the  sphyg- 
mograph  explained  two  apparently  contradictory  facts, 
both  of  which  are  perfectly  well  known: 

i.  The  smoker  says  he  feels  better  and  is  able  to 

think  faster  and  to  work  harder  just  after  smoking 

than  before  the  smoking. 


NICOTINE  AND  THE  SPHYGMOGRAPH  75 

2.  Athletic  coaches  say  tobacco  prevents  success. 
They  therefore  prohibit  its  use  by  their  men. 

It  is  as  if  one  honest  man  said,  "  Smoking  does  me 
good,"  while  another  man,  equally  honest,  says  posi- 
tively, "  Smoking  does  you  harm." 

To  reconcile  these  differences  we  turn  to  the  dia- 
grams borrowed  from  Dr.  McKeever's  record.  Notice 
that  one  of  these  shows  the  heart  beat  of  a  tired  young 
woman.  She  did  not  smoke,  but  she  was  on  the  verge 
of  nervous  prostration.  Compare  this  with  the  record 


SPHYGMOGRAPH  RECORD  OF  THE  HEART  BEAT  OF  A  YOUNG  WOMAN  ON 
THE  VERGE  OF  NERVOUS  PROSTRATION 

The  young  woman  does  not  smoke.    (From  Dr.  McKeever) 

of  the  vigorous  young  fellow  of  nineteen  who  did  not 
smoke.  It  shows  the  kind  of  work  a  healthy  boy's 
healthy  heart  should  do  for  him.  (See  p.  76.) 

Compare  both  these  records  with  the  wave  lines  in 
the  third  diagram  —  the  one  on  page  77.  See  that  first 
flattened-out  report  (i),  taken  before  the  smoking  began. 
It  is  quite  like  the  heart  beat  of  the  worn-out  young 
woman  —  faint,  weak,  lifeless.  No  wonder  the  fellow 
felt  dull! 

Effect  of  Smoking  on  the  Heart.  Study  the  next  report 
from  the  same  person.  See  the  beat  bound  upward 


76 


PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


when  the  smoking  begins  —  stronger,  faster,  more  vigor- 
ous. Fresh  blood  is  being  sent  to  every  part  of  the 
body.  The  brain  feels  it  first  and  becomes  more  active. 
The  smoker  says  he  "  feels  good "  —  and  no  wonder. 
Not  brain  alone,  but  muscles  and  liver,  stomach  and 
lungs  and  kidneys,  are  now  getting  better  blood  faster 
and  in  larger  quantity.  Even  the  farthest-off,  smallest 


SPHYGMOGRAPH  RECORDS  OF  THE  NORMAL  HEART 

i,  tracing  for  a  vigorous  fellow  of  nineteen;  does  not  smoke.    2,  healthy  heart 

beat ;  a  calm  temperament ;  does  not  smoke.  3,  heart  tracing  for  a  healthy  young 

woman ;  does  not  smoke.    (From  Dr.  McKeever) 

capillary  is  stretched  out  a  little  larger,  and  more  blood 
than  usual  hurries  through  it  for  a  few  minutes. 

But  this  flush  time  is  soon  over.  Fifteen  minutes 
have  passed.  The  sphygmograph  has  not  been  taken 
from  the  wrist;  it  is  still  making  records.  And  now 
see  what  has  happened.  All  the  splendid  vigor  has 
faded  out.  Once  again  the  heart  beats  almost  at  dead 
level.  Brain  cells  lose  their  activity;  muscles  and  liver, 
stomach,  lungs,  and  kidneys,  have  to  do  the  best  they 


NICOTINE  AND  THE  SPHYGMOGRAPH 


77 


can  with  the  slow-moving  blood.  It  brings  short  rations 
of  food  to  cells  that  cry  out  for  nourishment.  But,  sad 
to  say,  the  slow-pumping  heart  will  stay  in  charge  of  the 


SPHYGMOGRAPH  RECORDS  OF  THE  HEART  BEAT  OF  Two 
DIFFERENT  PERSONS 

i,  2,  3,  tracings  made  by  the  heart  of  a  young  man  of  nineteen:  I,  before  smok- 
ing; 2,  while  smoking;  3,  after  smoking.  He  began  to  smoke  cigarettes  at 
fifteen.  4,  5,  6,  tracings  made  by  the  heart  of  a  young  man  of  twenty :  4,  before 
smoking ;  5,  while  smoking ;  6,  after  smoking.  Began  smoking  at  thirteen  ;  now 
uses  a  strong  pipe.  (From  Dr.  McKeever) 

slow-moving  blood  until  the  next  cigarette  is  smoked. 
Then  it  will  jump  into  quick  action  again  for  a  few 
minutes. 


78          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

The  Tobacco  Heart.  This  is  why  a  smoker  must  often 
use  fifty  and  sixty  cigarettes  a  day  to  keep  his  heart 
up  to  the  mark.  This  is  how  a  healthy  heart  gets 
turned  into  a  weakened  heart.  This  is  why  the  steady 
smoker  often  fails  where  he  wishes  to  succeed.  And 
the  real  reason  for  all  this  is  the  double  character  of 
tobacco ;  it  is  a  stimulant,  and  it  is  also  a  narcotic 
poison.  The  smoker  craves  the  stimulation;  in  addition 
he  receives  the  poison  of  nicotine. 

How  Nicotine  gets  to  the  Heart.  When  a  man  lights 
his  cigarette,  the  woody  fiber  of  the  burning  tobacco 
turns  to  smoke  and  ashes,  and  at  the  same  time  the 
nicotine  turns  into  vapor.  If  now  the  man  draws  the 
smoke  into  his  lungs,  the  vaporized  nicotine  goes  with 
it.  But  after  reaching  the  lungs  they  separate.  The 
smoke  stays  on  all  the  delicate  tissues  of  the  lung  cells, 
which  is  bad  enough,  but  the  vapor  of  the  nicotine  is 
not  hindered  by  any  tissues.  Instead  it  passes  directly 
through  the  tissue  of  the  lung  cells,  enters  the  blood 
stream,  and  is  whirled  to  the  heart  by  the  straightest 
road  possible. 

Effect  of  Nicotine  on  the  Heart.  At  the  moment  it  ar- 
rives, the  sphygmograph  shows  what  the  poisoned  whip 
has  done.  It  has  lashed  the  heart  to  vigorous  action  — 
not  to  last  long,  however,  for  soon  the  same  sphyg- 
mograph shows  that  the  vigor  has  gone,  and  that  the 
permanent  condition  grows  worse  rather  than  better. 


NICOTINE  AND  THE  SPHYGMOGRAPH  79 

'  The  United  States  army  gives  proof  of  this.  At  an 
examination  for  the  military  school  at  West  Point,  one 
quarter  of  the  young  men  had  to  be  refused  admittance 
because  they  brought  upon  themselves  the  condition  of 
"  tobacco  heart  "  from  cigarette  smoking. 

At  another  time  a  set  of  412  boys  wished  to  enter  the 
naval  school  at  Annapolis.  They  were  examined  by  an 
officer  in  Peoria,  Illinois,  and  all  but  14  were  turned 
away.  As  was  said  by  the  examiner,  "  Of  the  398  re- 
jections, the  greater  number  were  on  account  of  weak 
hearts,  and  in  the  majority  of  cases  this  was  caused  by 
cigarette  smoking." 

Dr.  Seaver's  Tests.  In  1897,  at  Yale  University,  when 
Dr.  Seaver  made  his  thorough  study  of  the  matter,  he 
found  that  out  of  every  100  students  who  ranked  high- 
est, 5  were  smokers,  95  nonsmokers.  Among  the  rest  of 
the  students  at  that  time,  60  out  of  every  100  smoked. 
He  also  found  that,  on  the  average,  those  who  did  not 
smoke  gained  more  in  height  and  weight  and  girth  of 
chest  than  those  who  smoked. 

Remember  that  these  Yale  students  were  still  in  the 
growing  time  of  life ;  recall  the  facts  of  the  last  chapter ; 
then  imagine  what  it  means  to  have  a  young  and  grow- 
ing heart  attacked  over  and  over  again,  day  in  and  day 
out,  for  weeks  and  months  and  years,  by  a  poison  that 
does  its  worst  work  with  the  heart  itself.  It  seems  as  if 
no  harm  to  the  heart  could  be  much  more  serious. 


80          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Army  officers  and  doctors  declare  that  he  who  is  in* 
the  habit  of  using  cigarettes  should  be  careful  not  to  do 
anything  that  will  call  for  sudden,  or  violent,  or  vigorous 
use  of  muscles  and  heart.  Although  he  may  still  be  able 
to  run  as  fast  and  to  jump  as  high  as  his  friend  or  his 
schoolmate  who  does  not  smoke,  yet  the  probability  is 
that  he  has  the  sort  of  heart  that  the  army  refuses  to 
accept  —  the  heart  that  no  soldier  can  afford  to  own. 
And  the  man  who  is  afflicted  in  this  way  cannot  expect 
to  excel  on  the  athletic  field. 

In  this  connection  it  is  interesting  to  know  what 
the  leading  trainers  of  the  country  say  about  the  use 
of  tobacco. 

Mr.  McBride,  once  captain  of  the  Yale  football  team, 
wrote : 

It  is  absolutely  necessary  for  a  college  or  school  athlete  who  is  striv- 
ing to  win  a  place  on  any  team  to  have  endurance;  especially  is  this 
true  in  rowing  and  football.  This  can  be  accomplished  to  the  greatest 
degree  only  by  abstaining  from  the  use  of  tobacco  and  alcoholic  drinks 
while  in  training  for  said  team. 

Mr.  Edwards,  once  captain  of  the  Princeton  football 
team,  wrote : 

A  man  who  is  using  tobacco  and  alcohol  contrary  to  orders  during 
the  season  is  easily  detected,  and  is  dropped  from  the  squad. 

Mr.  A.  A.  Stagg  of  The  University  of  Chicago  wrote: 

We  have  never  had  a  really  successful  long-distance  runner  at  The 
University  of  Chicago  who  was  a  smoker.  In  football,  as  in  other 


NICOTINE  AND  THE  SPHYGMOGRAPH  8 1 

endurance  tests,  there  is  no  question  at  all  in  my  mind  that  the  man 
who  smokes  does  not  come  up  to  the  level  of  the  general  run  of 
nonsmokers. 

For  thirty  years  "  Mike  "  Donovan  was  the  athletic 
director  of  the  New  York  Athletic  Club,  and  from  his 
wide  experience  he  writes: 

Any  boy  who  smokes  can  never  hope  to  succeed  in  any  line  of 
endeavor,  as  smoking  weakens  the  heart  and  lungs,  ruins  the  stomach, 
and  affects  the  entire  nervous  system.  If  a  boy  or  a  young  man  expects 
to  amount  to  anything  in  athletics,  he  must  let  smoking  and  all  kinds  of 
liquor  alone.  They  are  rank  poison  to  his  athletic  ambitions. 

It  would  seem  then  that,  for  the  sake  of  the  heart  and 
for  the  sake  of  success,  cigarettes  must  be  put  aside. 
And  now  we  return  to  the  subject  of  circulation  and 
the  blood  stream. 

QUESTIONS 

1.  Describe  Dr.  McKeever's  tests  with  the  sphygmograph.  2.  Describe 
the  sphygmograph.  3.  Give  the  two  opposite  statements  made  by 
smokers  and  by  athletic  coaches.  4.  Show  by  the  chart  why  the  smoker 
feels  so  well  just  after  smoking.  5.  What  happens  to  the  heart  soon 
after  the  smoking  stops  ?  6.  Why  are  many  cigarettes  necessary  to 
make  one  feel  vigorous  ?  7.  What  objection  is  there  to  these  cigarettes  ? 
8.  How  does  nicotine  get  to  the  heart  ?  9.  What  effect  does  it  have  ? 
10.  Why  are  so  many  boys  rejected  by  the  medical  examiners  for  West 
Point  and  Annapolis?  11.  Describe  Dr.  Seaver's  tests  with  college 
boys.  12.  What  did  he  discover  about  their  scholarship?  about  their 
height,  weight,  and  girth  of  chest?  13.  If  a  person  is  in  the  habit  of 
using  cigarettes,  what  kinds  of  exercise  must  he  avoid  ?  14.  What  have 
some  of  the  athletic  directors  and  football  men  said  about  the  effect  of 
tobacco  on  health  ? 


CHAPTER  VI 


BLOOD  AND  LYMPH  INSIDE  AND  OUTSIDE  THE  TUBES 

Blood  Examination.    Tie  a  string  round  the  last  joint 
of  a  finger  of  your  left  hand.    Bend  the  tied  finger  over, 

to  increase  the  pressure  of 
the  blood  in  its  capillaries. 
Take  the  finest  needle  you 
have,  hold  it  in  a  candle  or 
a  lamp  flame  for  a  moment 
to  rid  it  of  microbes,  then 
stick  the  point  of  it  quickly 
into  the  dark-red  end  of  the 
finger.  You  will  tear  open 
several  capillaries  smaller 
than  the  needle,  and  a  good- 
sized  drop  will  ooze  through. 
Nevertheless  you  will  barely 
feel  the  prick.  Have  a 
piece  of  clean  glass  ready 
and  jostle  the  drop  of  blood 
down  upon  it.  Raise  the  glass,  hold  it  over  something 
white,  and  notice  the  color.  You  will  see  that  it  has  a 

yellow   tinge.     Leave    it    on   the   glass   for   five  or  six 

82 


PREPARED  TO  DRAW  A  DROP  OF 
BLOOD 


BLOOD  AND  LYMPH 


minutes,  then  look  at  it  again.  You  will  find  it  turned 
to  jelly.  Set  a  tumbler  over  it  and  let  it  remain  undis- 
turbed for  half  an  hour  or  so.  At  the  end  of  that  time 
you  will  see  a  bit  of  red  substance  floating  in  a  small 
drop  of  liquid  which  is 
almost  colorless. 

Coagulation.  Look  back 
at  the  finger  you  pricked, 
and  if  you  did  not  wipe 
it  off  clean  after  you 
did  the  pricking,  you  will 
see  that  there,  too,  a  rem- 
nant of  the  blood  has 
hardened  round  the  edges 
of  the  tiny  wound.  This 
hardening  of  part  of  the 
blood  is  called  coagula- 
tion. It  will  remind  you 
of  the  statement  so  often 
made,  that  the  best  healer 
for  a  wound  is  the  blood 
which  oozes  through  it.  Healing  goes  on  beneath  it. 

Blood  under  the  Microscope.  If  we  could  add  the  use 
of  a  microscope  to  our  experiments,  we  would  draw  a 
second  drop  of  blood,  and  we  should  learn  a  number 
of  important  facts  about  its  composition.  We  should 
then  recognize  it  as  a  liquid  with  multitudes  of  small 


CORPUSCLES  SEEN  BY  THE  AID  OF  A 
MICROSCOPE 

A  few  red  ones  are  highly  magnified. 
Those  that  are  less  magnified  show  how 
corpuscles  stick  together  after  blood  is 
drawn  from  the  body.  Two  white  corpus- 
cles are  given 


84          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

red   and  white  objects  floating  in  it.     Blood   is   indeed 
a  mixture  of  three  things : 

1.  Red  objects,  called  red  corpuscles,  which  give  the 
blood  its  color.    There  are  millions  of  these  in  each 
drop   of   healthy  blood.     Imagine   then   their  size ! 
Each  is  round  and  flat,  with  a  concave  center,  and 
these  microscopic  disks  are  the  important  oxygen 
carriers  of  the  body.    They  never  leave  the  blood 
tubes  unless  these  tubes  themselves  are  crushed,  or 
cut,  or  forced  to  leak  through  accident  or  disease. 

It  has  been  estimated  that  the  life  period  of  a  red 
corpuscle  is  about  six  weeks,  that  there  are  perhaps 
twenty-five  millions  of  millions  of  them  in  the  blood 
of  the  average  man,  that  seven  millions  die  with 
each  tick  of  the  clock,  and  that  during  the  same 
clock  tick  seven  other  millions  are  created  by  the 
body  to  replace  them.  Do  not  try  to  memorize 
these  figures.  They  are  stated  here  just  to  give  a 
notion  of  the  vast  numbers  of  the  blood  corpuscles. 

2.  The  liquid  part,  called  plasma.     This  is  quite 
transparent  and  almost  colorless.    A  little  over  one 
half  of  each  quart  of  blood  is  plasma;  the  rest  is 
the  corpuscles. 

3.  Colorless   objects,   called  white   corpuscles.     Of 
these  there  are  usually  from  five  to  seven  thousand 
in   each    cubic    millimeter,1   although    the    number 

•    . "-•  i  Fifty  cubic  millimeters  make  a  drop  of  water. 


BLOOD  AND  LYMPH 


varies  from  time  to  time.  White  corpuscles  are 
specks  of  living,  jellylike  substance  which  change 
their  shape  constantly.  They  not  only  travel  with 
the  other  corpuscles ,  in  the  plasma,  but  they  also 
work  their  way  through  the  walls  of  the  capillaries 
and  wander  here  and  there  in  the  body.  They  are 
soldiers  and  scaven- 
gers too,  for,  as  the 
last  chapter  of  this 
book  shows,  they  not 
only  destroy  harmful 
microbes  when  they 
find  them,  but  also 
help  more  than  any 
other  part  of  the  blood 
in  healing  a  wound. 
The  Blood's  Important 
Work.  Plasma,  red  corpus- 
cles, and  white  corpuscles 
are  all  that  the  microscope 

shows  when  we  use  it  for  the  study  of  blood.  But  a 
chemist  will  take  the  same  blood,  analyze  it  in  his  labo- 
ratory, and  prove  that  it  is  made  up  of  many  different 
substances  of  which  we  have  not  so  much  as  heard  the 
names  —  substances  needed,  however,  for  the  work  which 
each  separate  part  of  the  body  is  doing.  He  will  tell 
us  that  within  the  blood  is  all  that  is  needed  for  the 


RED  AND  WHITE  CORPUSCLES 

Four  different  shapes  and  four  positions 
taken  by  the  same  white  corpuscle 


86 


PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


manufacture  of  bone,  muscle,  hair,  tendons,  tears,  fat,  and 
finger  nails;  that  it  is  the  source  of  supply  for  all  that 
lies  under  the  cover  of  the  skin,  the  storehouse  for  more 
treasures  than  we  have  even  dreamed  about ;  and  that  it 
is  easy  to  enrich  or  to  impoverish  the  blood  by  our 
treatment  of  the  body.  It  is,  indeed,  for  the  benefit  of 
the  blood  that  food  and  air  do  the  important  work  which 

wrill  be  studied  later. 

But  the  question  is,  How  can 
blood  do  so  much  when  it  stays 
all  the  time  within  the  confines 
of  the  tubes?  Nothing  but  an 
experiment  can  clearly  answer 
this  question,  and  we  can  make 
this  for  ourselves. 

Exchanges  along  the  Tubes.  Get 
from  the  butcher  a  piece  of  fresh 
animal  membrane — a  bladder  will 
do.  Fill  a  small  glass  with  fresh 

water,  tie  the  membrane  tightly  over  it,  set  the  glass 
into  a  much  larger  one  filled  with  salted  water,  letting 
the  water  cover  it,  and  leave  the  two  glasses  together 
overnight.  In  the  morning  take  out  the  smaller 
glass,  unfasten  the  membrane,  and  taste  the  water 
which  was  fresh  and  sweet  the  night  before.  You  will 
find  that  it  is  now  distinctly  salt.  Taste  the  water  in  the 
larger .  glass.  You  will  find  that  it  has  grown  fresher. 


ONE  GLASS  WITHIN  THE 
OTHER 

The  smaller  glass  holds  fresh 

water,  the  larger  holds  water 

and  salt 


BLOOD  AND  LYMPH  87 

In  this  exchange  the  salt  in  the  liquid  has  acted 
according  to  a  universal  law.  Salt  is  indeed  one  of 
the  many  substances  which  pass  easily  back  and  forth 
through  any  moist  animal  membrane.  This  process  is 
called  osmosis. 

Put  sugar  into  one  glass  of  water  and  soda  into 
another.  Let  a  membrane  be  stretched  between  them, 
as  was  done  in  the  fresh-and-salt-water  experiment,  and 
before  long  you  will  have  two  liquids  that  have  become 
strangely  alike.  The  different  substances  in  the  solutions 
have  changed  places  through  the  membrane,  according 
to  the  law  of  osmosis. 

Gas  Exchanges  in  the  Blood.  Even  gases  are  subject 
to  the  same  law.  Men  who  know  how  to  handle  such 
things  can  put  oxygen  in  one  tube  and  carbon  dioxide 
in  another.  They  can  then  separate  the  gases  by  a 
piece  of  animal  membrane  stretched  between  the  tubes, 
and  they  discover  that  the  two  gases  refuse  to  stay  apart. 
Indeed  so  much  of  each  finds  its  way  through  the  par- 
tition that  soon  there  is  a  mixture  of  the  two  on  either 
side  of  the  membrane. 

Experiments  such  as  these  answer  the  query  as  to 
how  the  body  gets  what  it  needs  from  the  blood.  Every- 
where it  is  the  animal  membrane  of  the  tubes  themselves 
which  separates  the  blood  within  the  tubes  from  a  cer- 
tain other  liquid  which  lies  close  about  them  on  the 
outside. 


88          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Lymph  and  Oxidation.  However  small  and  however 
thin-walled  the  blood  vessels  may  be,  there  is  always 
this  clear  liquid,  called  lymph,  bathing  the  outside  of  the 
capillaries  like  a  sort  of  colorless  sap  in  the  body  and 
making  its  exchanges  with  the  contents  of  the  liquid 
within  the  hairlike  tubes.  Moreover,  this  lymph,  which 
soaks  slowly  but  constantly  through  every  tissue  of  the 
body,  is  laden  with  carbon  dioxide,  which  it  has  received 
from  the  tissues  themselves.  The  blood  is  rich  in  oxy- 
gen, and  it  is  separated  from  the  lymph  only  by  the  walls 
of  the  capillaries.  In  view  of  this,  what  could  be  more 
natural  than  the  thing  which  comes  to  pass  ?  The  gases 
in  the  lymph  and  in  the  blood  change  places  with  each 
other  as  promptly  as  do  the  liquid  materials  which  are 
also  in  the  lymph  and  in  the  blood.  And  this  exchange 
is  part  of  the  great  process  known  as  the  oxidation  of 
the  blood. 

It  is  evident,  then,  that  lymph  is  as  important  to  us 
as  is  blood  itself.  In  fact,  the  two  must  always  travel 
side  by  side.  They  are  indispensable  to  each  other. 
Without  the  one  the  other  is  useless.  Three  statements 
will  show  how  close  the  relation  is : 

i.  Blood  in  the  arteries  is  the  result  of  the  food 
we  eat  and  of  the  air  we  breathe.  It  contains  every 
supply  that  any  part  of  the  body  needs  for  nourish- 
ment, for  strength,  and  for  growth,  and  it  is  sent 
here  and  there  by  the  action  of  the  heart. 


BLOOD  AND  LYMPH  89 

2.  Blood  in   the  veins  is  what    is   left  after  the 
lymph    has    taken    from   it    the   oxygen   and    other 
nourishment  which  the  body  needs,  and  given   in 
exchange  the  carbon  dioxide  and  other  waste  which 
must  be  carried  off.    In  other  words,  venous  blood 
contains    much   waste  from    the  tissues   and   little 
nourishment   for  the   tissues;    while  arterial   blood 
is  rich  in  nourishment  for  the  tissues  and  contains 
little  waste. 

3.  Lymph  is  made  up  of  rich  nourishing  plasma 
derived  from  the  blood,  on  its  way  to  the  tissues,  and 
of  waste  material  from  the  body,  which  will  soon 
pass  into  the  capillaries,  be  carried  onward  in  the 
veins,  and  be  disposed  of  as  we  shall  learn  hereafter. 
Lymph  is  also  the  highroad  to  the  blood  for  many 
substances  that  are  being  manufactured  by  differ- 
ent organs  of  the  body.   These  manufactured  arti- 
cles must  find  their  way  into  the  blood,  for  only 
through  circulation  will  they  ever  be  able  to  reach 
their  destination. 

The  Lymphatic  System.  The  origin  of  the  lymphatic 
tubes  is  strangely  interesting  for  the  simple  reason  that 
it  is  so  very  indefinite.  Each  seems  to  begin  about  as 
irregularly  as  a  stream  that  gathers  water  in  a  swamp. 

As  we  know,  blood  vessels  are  a  closed  system  of 
tubes  with  a  stream  of  blood  sweeping  through  them 
endlessly  —  going  ever  round  and  round,  from  the  heart 


90          PHYSIOLOGY,  HYGIENE,  AND   SANITATION 

through  the  arteries,  the  capillaries,  and  the  veins,  back  to 
the  heart  again.  In  this  great  system  not  even  the  small- 
est tube  in  the  remotest  region  of  the  body  is  left  with 
an  open  mouth.  The  lymphatic  system,  however,  works 
on  quite  a  different  basis.  Here  the  vast  multitudes  of 


A  CLUSTER  OF  TUBES 
Look  for  those  with  open  mouths  ;  A,  artery ;   V,  vein ;  Z,  Z,  Z,  lymphatics 

the  smallest  tubes  seem  to  be  really  little  more  than 
open  mouths  into  which  liquid  is  gradually  making  its 
way.  Bear  this  in  mind  while  the  facts  are  given  as 
definite  statements: 

i.  Each  blood  vessel  of  the  body  makes  its  way 
through  a  meshwork  of  tissues. 


BLOOD  AND  LYMPH 


2.  Everywhere  among  these  intertwined  tissues 
there  is  a  colorless  liquid  called  lymph.   The  capil- 
laries of  the  blood  are  surrounded  by  this  lymph, 
just  as  grass  and  weeds  are  surrounded  by  water  in 
a  swamp.    Lymph  looks 

like  the   plasma  of  the 
blood. 

3.  Lymph  and  plasma 
are    constantly    making 
exchanges    through   the 
walls  of  the  blood  vessels. 

4.  Plasma   is   getting 
from  the  lymph  all  that 
the  body  is  through  with 
—  all  that  should  go  on 
in  the  blood  and  be  dis- 
posed of  elsewhere. 

5.  Lymph    is  getting 
from  the  plasma  all  the 

nourishment    which     the  LYMPHATICS  OF  THE  HAND 

tissues  need. 

6.  Opening  away  from 

the  loose  fibers  through  which  the  blood  vessels  run, 
and  in  which  all  this  exchange  is  going  on,  there 
are  other  tubes  about  as  small  as  the  capillaries; 
and  into  the  open  mouths  of  these  tubes  the  lymph 
from  the  tissues  gradually  makes  its  way. 


Smaller  tubes  lie  near  the  surface, 
larger  ones  lie  deeper 


92          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

7.  Vigorous  exercise  hastens  the  flow  of  lymph 
no  less  than  of  blood,  and  the  tissues  are  benefited 

thereby. 

8.  From   start  to  finish 
the    lymphatic    tubes,  like 
the  veins,  progress  in  size 
from     smaller     to     larger. 
They    are    also    provided 
with   inside  pockets  quite 
like    those    of    the    veins. 
These  pocket  valves  keep 
the    lymph    from    moving 
backward  and  help  to  send 
it  constantly  onward,  that 
it  may  at  last  mingle  with 
the  great  stream  of  blood 
that  goes  to  the  heart. 

9.  This    progress    from 
smaller  to  larger  tubes  con- 
tinues until  all  the  lymph 
of  the  body  finds  its  way 
into  two  large  lymph  tubes, 
one  on  each  side   of   the 
neck.     These   empty  into 
two  large  veins,  and  thence- 

VEINS  AND  LYMPH  TUBES  r  ,    -,  •>  i    i  i       j 

forward   lymph  and   blood 

The  lymph  tubes  are  white  and  are  .      .  , 

seen  to  empty  into  the  large  veins      gO    On    their    Way    together 


BLOOD  AND  LYMPH  93 

to  the  heart.  The  lymph,  with  all  it  has  gathered, 
has  now  entered  the  circulatory  system,  and  thus 
the  contributions  from  the  many  different  organs 
of  the  body  will  be  distributed  by  means  of  the 
blood.  The  movement  of  this  fluid  continues  dur- 
ing life,  for  the  lymph  vessels  and  lymph  spaces 
can  never  be  empty  as  long  as  the  organs  of  the 
body  are  at  work. 

A   special  point  to   remember  is  that   blood  vessels 

and  tissues  are  as  much  better  off  when  fresh  lymph 

surrounds  them  as  are  fish  when  they  are  in  fresh  water. 

The  next  chapter  shows  what  happens  when  alcohol 

enters  the  streams  of  blood  and  lymph. 

QUESTIONS 

1.  How  would  you  get  a  drop  of  blood  for  examination?  2.  What 
is  the  color  of  the  blood?  3.  How  do  you  know  that  blood  hardens 
soon  after  it  leaves  the  body  ?  4.  What  becomes  of  it  after  it  has 
been  left  standing  about  half  an  hour?  5.  What  is  coagulation? 
6.  Of  what  value  is  coagulation  in  healing  a  wound?  7.  What  three 
things  mixed  together  form  blood  ?  8.  Describe  red  corpuscles  ;  white 
corpuscles.  9.  What  is  the  liquid  part  of  blood  called?  10.  What  can 
a  chemist  find  out  about  blood  ? 

11.  Describe  experiments  which  prove  that  certain  substances  can 
pass  through  a  moist  animal  membrane.  12.  What  is  this  process 
called?  13.  What  exchange  of  liquids  and  gases  in  the  body  is  ex- 
plained by  these  experiments  ?  14.  What  is  lymph  like,  and  where  is 
it  found?  15.  What  gas  passes  from  the  tissues  of  the  body  into  the 
lymph?  16.  How  does  it  reach  the  red  corpuscles?  17.  How  does 


94          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

oxygen  from  the  red  corpuscles  get  to  the  tissues?     18.  Which  two 
gases  change  places  in  the  red  corpuscles  ? 

19.  Describe  the  blood  in  the  arteries.  20.  Describe  the  blood  in 
the  veins.  21.  Describe  the  origin  of  the  lymphatic  tubes.  22.  What  is 
the  difference  between  the  system  of  blood  vessels  and  the  system  of 
lymphatic  tubes?  23.  What  does  lymph  look  like?  24.  What  does 
plasma  receive  from  lymph  ?  25.  What  does  lymph  receive  from 
plasma?  26.  Of  what  use  are  the  pocket  valves  in  the  lining  of  the 
lymph  tubes?  27.  How  does  vigorous  exercise  help  the  body  through 
the  lymph  ?  28.  Why  is  it  well  for  tissues  to  be  surrounded  by  fresh 
lymph  ? 


CHAPTER  VII 

ALCOHOL  IN  THE  BLOOD  STREAM 

Slow  Circulation  of  the  Blood.  Red  eyelids  and  a 
pink  nose  tell  plain  facts  about  the  state  of  the  capil- 
laries in  those  particular  regions,  but  the  mere  fact 
that  a  man  has  a  red  nose  signifies  very  little  about 
his  general  health.  Many  a  hearty  sea  captain  has 
carried  such  a  nose  with  him  through  half  a  century. 
He  has  lived  to  be  eighty  years  old  or  older,  and  the 
shade  of  his  sunburned  nose  has  mattered  little  to  him. 
Sometimes,  however,  the  color  of  a  man's  nose  is  a 
sign  of  general  internal  conditions.  It  may  show  that 
the  capillaries  throughout  his  body  are  loaded  with 
slow-moving  blood,  and  this  condition  of  the  capillaries 
throws  a  flood  of  light  on  the  sort  of  work  which  the 
heart  itself  is  doing. 

Judging    by   facts   which    we    have    already    learned, 
three  points  are  clear: 

i.  Slow-moving  blood  is  more  impure  than  fast- 
moving  blood.  For  this  reason  such  blood  is  always 
a  disadvantage  to  any  part  of  the  body  in  which 
it  tarries. 

95 


96          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

2.  The  mere  fact  that  blood  is  moving  fast  shows 
that  impurities  are  being  hastened  out  of  the  way 
and  that  fresh  material  is  being  supplied  to  lymph 
and  tissue. 

3.  The  blood  vessels  must  always  be  in  a  healthy, 
vigorous,  elastic  condition  if  the  best  exchanges  are 
to  be  made  through  their  walls. 

Alcohol  and  the  Heart  Beat.  In  view  of  these  state- 
ments we  are  ready  to  understand  a  set  of  discoveries 
about  circulation  which  have  been  made  during  the  past 
few  years.  It  appears  that  for  many  previous  years 
educated  doctors  and  ignorant  men  alike  believed  that 
alcohol  was  a  genuine  help  to  the  vigor  of  the  circula- 
tion. Thousands  of  men  thought  they  had  proved  this 
by  personal  experience.  At  different  times,  and  in  dif- 
ferent places,  they  had  taken  alcohol  in  large  doses  or 
in  small  doses,  and  after  the  drinking  they  had  tested 
their  hearts  and  found  by  counting  the  pulse  that  the 
number  of  heart  beats  had  increased.  They  had  felt  the 
pleasurable  effect  of  blood  bounding  faster  through  their 
veins,  and  it  was  most  natural  for  them  to  believe  that 
the  alcohol  which  they  had  taken  had  strengthened  the 
heart,  just  as  food  strengthens  the  body. 

Testing  the  Heart  Beat  with  the  Sphygmograph.  In 
time,  however,  came  the  sphygmograph,  with  its  tests  of 
vigorous  and  languid  hearts.  It  is  in  wide  use  to-day, 
because  doctors  find  that  they  can  judge  in  a  general 


ALCOHOL  IN  THE  BLOOD  STREAM  97 

way  as  to  whether  a  man  is  well  or  not  by  the  vigor  or 
the  languor  with  which  his  heart  does  its  work. 

Doctors  and  teachers  alike  were  now  astonished. 
They  took  -alcoh6l  themselves;  they  gave  it  to  their 
friends  and  their  patients;  they  studied  the  heart  and 
found  that  its  throbs  had  increased  in  number.  But 
when,  in  this  condition,  they  used  the  sphygmograph, 
they  were  surprised  to  see  that  the  heart  was  not  put- 
ting as  much  power  into  each  stroke  after  the  alcohol 
was  taken  as  it  had  done  before. 

Alcohol  and  Heart  Vigor.  Over  and  over  again  the  tests 
were  made,  with  the  same  result.  Each  trial  showed  that 
although  the  heart  was  pumping  faster  than  usual,  it  was 
nevertheless  doing  its  work  with  less  vigor.  It  was  using 
less  force  for  the  increased  number  of  strokes  than  it 
had  used  for  the  smaller  number  made  before  alcohol 
had  been  taken  into  the  blood. 

Testimony  of  this  sort  gave  a  new  color  to  the  practice 
of  using  alcohol  when  the  heart  needs  to  be  strength- 
ened. Doctors  in  every  land  had  to  yield  to  the  evi- 
dence of  their  senses.  They  had  to  believe  that,  instead 
of  giving  strength,  alcohol  actually  robs  the  heart  of  a 
part  of  the  strength  which  it  had  before  the  alcohol  was 
taken.  This  was  a  hard  thing  to  believe,  yet  to-day  the 
facts  of  the  case  are  accepted  by  all  up-to-date,  intelligent 
people.  And  this  is  why  our  best  doctors  are  giving  so 
much  less  alcohol  nowadays  than  in  former  times. 


98          PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

First  Effects  of  Alcohol.   Here  are  a  few  of  the  most  im- 
portant points  about  the  effects  of  alcohol  on  the  body: 

1.  Healthy   tubes   that   carry   blood   are   elastic. 
They  stretch  out  when  blood  is  pumped  into  them 
by  the  heart,  and    they   contract   firmly   again  as 
they  send  the  blood  onward. 

2.  The  first  effect  of  alcohol  in  the  body  is  to 
paralyze  in  a  very  slight  way  every  tube  that  has 
anything   to   do   with    carrying    blood    hither   and 
thither.   This  means  that  alcohol  is  a  narcotic  and 
not  a  stimulant.1 

3.  Because  the  tubes  are  slightly  paralyzed  they 
are  more  relaxed  than  formerly.   They  contract  less. 
They  therefore  offer  less  resistance  to  the  blood 
that  is  pumped  into  them.    After  they  are  full  they 
stay  relaxed  and  do  not  have  the  elastic  power  to 
pull  themselves  firmly  into  shape  again. 

4.  The   heart   is  also  slightly  paralyzed   by  the 
alcohol.    Still,  those  countless  relaxed  tubes  offer  so 
little  resistance   that  the   heart   pumps   the  blood 
into  them  with  less  effort  than  formerly,  and,  as  a 
result,  contracts  more  frequently. 

Thus  far,  however,  no  harm  appears.   The  capillaries 
are  full  of  blood;  the  man  feels  the  warmer  for  it,  and 


1  A  narcotic  is  something  that  lowers  the  vitality  of  the  body  and  may  harm  it. 
A  stimulant  is  something  that  stirs  even  a  tired  organ  or  a  tired  body  to  activity. 
Certain  stimulants  are  dangerous  things  to  use. 


ALCOHOL  IN  THE  BLOOD  STREAM  99 

his  heart  is  beating  a  trifle  faster  than  usual.    That  is  all. 
But  now  begins  the  chapter  of  damages  and  calamities. 

The  Real  Harm  of  Alcohol.  During  the  time  that  the 
heart  itself  is  weakened,  it  cannot  put  force  enough  into 
each  stroke  to  drive  the  blood  on  in  spite  of  the  relaxed 
state  of  the  walls  of  the  tubes.  Various  results  now 
follow.  Blood  moves  more  slowly  through  the  tubes ; 
it  is  slow  in  carrying  away  broken-down  tissue  from 
the  lymph;  it  is  slow  in  bringing  fresh  nourishment 
for  the  rebuilding  of  the  tissues. 

In  the  meantime,  if  alcohol  continues  to  be  taken,  the 
capillaries  may  be  kept  stretched  so  long  as  to  lose  all 
power  to  contract.  If  this  state  continues,  the  walls  them- 
selves end  by  becoming  thicker  and  stiffer.  The  work  of 
exchange  which  should  go  on  at  a  rapid  pace  through, 
them  is  thus  interfered  with,  and  the  health  of  the 
drinker  suffers  in  numerous  ways. 

This  is  no  fancy  picture.  It  is  simply  the  history  of 
circulation  in  such  persons  as  are  ignorant  enough  to 
be  willing  to  rob  themselves  of  the  service  which  their 
blood  and  their  blood  vessels  should  do  for  them. 

Fat  about  the  Heart.  The  gravest  aspect  of  the  affair, 
however,  is  in  connection  with  what  happens  to  the 
heart.  Because  this  tireless  pump  is  weaker  than  it 
was,  it  also  becomes  stretched ;  and  as  it  cannot  do 
full  work,  it  lacks  the  exercise  which  would  keep  it  in 
vigorous  health.  It  grows  flabby,  as  does  an  unused  arm. 


100       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Fat  gathers  not  only  between  the  fibers  but  also  within 
the  body  of  each  separate  fiber.  In  this  latter  case,  fat 
takes  the  place  of  tissue  itself,  and  then  occurs  what 
is  called  fatty  degeneration  of  the  heart  —  a  most  seri- 
ous condition.  For  a  heart  of  this  sort  is  too  weak  to 
send  blood  onward  as  rapidly  as  it  should  go.  This 


Two  HEARTS  SIDE  BY  SIDE 

On  the  left  the  heart  is  normal ;  on  the  right  it  is  enlarged  and  weakened  by  fat 
(Copied  from  Alcohol  and  the  Human  Body,  by  Horsley  and  Sturge) 

means  that  circulation  throughout  the  entire  body  is 
hindered,  and  that  each  great  organ  suffers  for  lack 
of  what  it  should  get  through  fresh  supplies  of  blood. 
Evidently,  then,  he  who  owns  a  fatty  heart,  weakened 
from  any  cause,  is  far  less  sure  of  continued  life  than 
he  might  have  been.  Since  he  secured  this  condition 
through  ignorance,  he  is  not  to  blame.  But  sad  as  is 


ALCOHOL  IN  THE  BLOODSTREAM  "l6t 

the  fact,  ignorance  never  saves  men  from  the  results 
of  their  ignorance. 

Weakened  Heart  and  Arteries.  Why  do  surgeons  dread 
to  do  anything  for  the  man  who  uses  alcohol  ?  Because 
they  know  only  too  well  that  the  power  of  his  heart 
and  the  elasticity  of  his  arteries  have  been  so  reduced 
that  his  heart  may  not  rally  after  the  operation.  In 
writing  of  this  danger,  Sir  Frederick  Treves  says: 

Having  spent  the  greater  part  of  my  life  in  operating,  I  can  assure 
you  that  there  are  some  patients  that  I  don't  mind  operating  upon  and 
some  that  I  do ;  but  the  person  of  all  others  that  I  dread  to  see  enter 
the  operating  theater  is  the  drinker.  He  is  the  most  dangerous  feature 
in  connection  with  the  surgical  life. 

It  is  because  of  this  constant  state  of  relaxed  capil- 
laries that  the  nose  of  the  drinker  stays  red.  In  his 
case  the  nose  is  frequently  a  reliable  sign  of  internal 
conditions.  Any  man  with  weakened  heart  and  arteries 
should  have  nothing  to  do  with  such  running  as  is  de- 
scribed in  the  next  chapter.  It  may  put  his  life  in  peril. 

QUESTIONS 

1.  When  the  nose  or  any  other  part  of  the  body  is  red,  what  do 
we  understand  about  the  capillaries  just  there?  2.  What  objection  is 
there  to  having  blood  move  slowly  through  the  capillaries?  3.  Mention 
two  advantages  that  are  connected  with  fast-moving  blood.  4.  Why 
should  the  walls  of  the  blood  vessels  be  kept  healthy,  vigorous,  and 
elastic?  5.  What  did  doctors  formerly  think  about  the  connection 
between  alcohol  and  circulation  ?  6.  After  a  man  takes  alcohol  does  his 


102        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

heart  beat  faster  or  slower?  7.  What  dees  the  sphygmograph  show 
about  the  power  of  the  heart  before  and  after  alcohol  has  been  used  ? 
8.  Does  this  prove  that  the  heart  receives  strength  or  is  robbed  of 
strength  by  the  alcohol  ?  9.  What  is  the  natural  condition  of  the  blood 
tubes?  10.  Are  they  elastic  or  nonelastic?  11.  What  effect  does 
alcohol  have  on  them?  12.  Why  is  this  harmful?  13.  What  is  a 
narcotic?  a  stimulant?  14.  What  effect  has  alcohol  on  the  heart? 
15.  Describe  the  result  when  both  blood  tubes  and  heart  are  thus 
weakened.  16.  What  finally  happens  to  the  walls  of  the  tubes  ? 
17.  What  effect  does  this  have  on  the  exchanges  between  plasma  and 
lymph  ?  18.  Why  does  the  body  suffer  when  the  exchanges  are  made 
slowly?  19.  Describe  the  condition  of  the  heart  after  it  has  been 
weakened  by  alcohol.  20.  What  objection  is  there  to  fat  among  the 
fibers  of  the  heart?  21.  Why  do  surgeons  dread  to  operate  on  a  man 
who  uses  alcohol  ? 


CHAPTER  VIII 


TRAINED  AND  UNTRAINED  LUNGS 

What  is  Breathlessness  ?  If  you  were  ever  thoroughly 
out  of  breath,  recall  the  sensations  you  had  at  the  time. 
Perhaps  you  were  trying 
to  catch  a  train ;  perhaps 
you  were  running  in  a  re- 
lay race.  In  either  case 
you  felt  that  you  must 
reach  the  goal  at  all  haz- 
ards, and  you  ran  as  you 
had  never  run  before. 

Your  breath  came  and 
went  freely,  and  during 
the  first  few  moments  you 
drew  deep,  long  breaths 
of  equal  length.  .Soon, 
however,  you  found  that 
each  breath  was  shorter  ^ 

BREATHLESS  AT  THE  END  OF  THE  RACE 

than  the  last.   You  began 

to  be  uncomfortable.    There  was  a  tight  feeling  within 

you,  as  if  an  iron  band  were  closing  itself  about  your 

chest;    as    if    it    prevented    you    from    expanding   your 

103 


104        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

lungs    to    their    full    size.     You    wondered    how    much 
longer  you  could  keep  it  up. 

But  why  were  you  breathless?  To  answer  the  ques- 
tion, follow  once  more  the  condition  of  muscle  and 
bone,  tendon  and  heart,  lungs  and  blood  vessels,  while 


6789 

NINE  VIEWS  OF  THE  SAME  MAN  AS  HE  RAN 

A  different  set  of  muscles  is  at  work  in  each  position,  so  that  altogether  many 
muscles  are  used  in  running 

(After  Schmidt) 

you  were  running.  Think  for  a  moment  of  your  in- 
elastic tendons  as  they  stayed  firmly  gripped  to  their 
bone  attachments.  Remember  how  each  one  of  multi- 
tudes of  muscles,  large  and  small,  shortened  and  length- 
ened as  by  means  of  their  tendons  they  pulled  those 
leg  bones  of  yours  up  and  down  and  kept  them  at 
work.  Remember  that  neither  arms,  back,  neck,  nor  any 
other  part  of  your  body  was  relaxed  as  you  ran,  but  that 
every  muscle  seemed  to  work  hard  in  keeping  time  and 


TRAINED  AND  UNTRAINED  LUNGS  105 

step  with  the  movement  of  the  legs.  Remember  that 
such  violent  action  as  this  means  that  changes  are 
going  on  in  the  substance  of  the  living  tissue  which 
is  exercised ;  that  these  changes  involve  the  giving  off 
of  unusual  quantities  of  carbon  dioxide;  that  oxygen 
is  needed  by  the  working  fibers;  and  that  iii  order  to 
supply  the  oxygen  and  to  carry  off  the  carbon  dioxide 
and  other  waste  products,  fresh  streams  of  blood  must  be 
hastened  to  the  active  muscles  with  ever-increasing  speed. 
The  most  immediate,  imperative  need  of  each  working 
fiber  is  to  get  rid  of  the  excess  of  carbon  dioxide. 

The  Cause  of  Breathlessness.    There  are  three  things 
which  bring  about  such  a  condition  of  breathlessness : 

1.  Exercise  violent  enough  to  compel  the  fibers 
of   the    muscles    to  produce  unusual  quantities  of 
carbon  dioxide.    As  this  gas  is  produced,  oxygen  is 
demanded  by  the  fibers.    It  is,  indeed,  as  if  they 
themselves  were  breathing. 

2.  The  activity  of  the  chest  walls  as  they  expel 
the  carbon  dioxide  from  the  air  sacs  of  the  lungs 
and  replace  it  with  air  containing  oxygen. 

3.  The    rapid  work  of   the  heart  as  it   receives 
larger  amounts  of  impure  blood  than  usual  through 
the  veins  and  sends  arterial  blood  to  the  tissues  to 
carry  oxygen    and    to   bring  away  carbon  dioxide. 
To  a  large  extent   it   is   this   forced  work  of  the 
heart  that  explains  the  feeling  of  breathlessness. 


106        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

We  were  speaking  of  this  matter  the  other  day,  and 
my  friend,  who  teaches  physiology,  said : 

People  used  to  say  that  a  man  was  breathless  because  there  was 
more  carbon  dioxide  in  his  blood  than  he  could  expel  through  his  lungs. 
But  we  know  better  now.  We  know  that  it  is  n't  so  much  the  carbon 
dioxide  —  although  of  course  that  has  to  be  driven  off  —  as  it  is  the 
overtaxed  heart  that  makes  us  breathless. 

Boys  come  to  me  for  examination,  and  I  tell  them  that  the  heart 
gets  tired  from  overwork,  just  as  the  biceps  does,  and  that  it  is  quite 
as  possible  to  strengthen  the  heart  by  training  as  to  strengthen  the 
biceps.  At  first  I  put  the  boys  on  easy  exercises  that  tax  the  heart  but 
little ;  then  day  by  day  I  give  what  is  harder  until,  almost  before  they 
know  it,  those  boys  have  developed  hearts  that  are  strong  enough  to  do 
hard  work  without  making  them  breathless.  At  the  same  time  they  have 
trained  the  heart  and  lungs  to  work  together  in  ventilating  the  blood. 

Speed  and  Breathlessness.  The  fact  is  that  we  grow 
breathless  in  proportion  to  the  force  which  we  put  into 
any  exercise  in  a  given  length  of  time ;  that  is,  the  faster 
we  do  the  same  thing,  the  more  quickly  will  breathless- 
ness  overtake  us.  It  is  easy,  therefore,  to  understand 
an  opposite  condition,  and  to  believe  that  the  quieter 
we  are  the  less  oxygen  the  tissues  will  use  and  the  less 
carbon  dioxide  the  body  will  have  to  get  rid  of. 

While  we  sleep  we  give  off  the  least  carbon  dioxide. 
When  we  sit  up  the  quantity  is  almost  doubled.  When 
we  run  the  change  is  striking,  for  now,  during  every 
minute  of  exercise,  the  blood  carries  to  the  lungs  over 
four  times  as  much  carbon  dioxide  as  it  carried  while 
we  were  asleep.  The  proportion  is  not  always  the  same. 


TRAINED  AND  UNTRAINED  LUNGS  107 

Those  who  train  for  athletic  sports  take  the  facts  about 
oxygen  and  carbon  dioxide  into  account.  They  learn  to 
manage  their  running  and  the  work  of  heart  and  lungs 
in  such  a  way  that  neither  will  be  overtaxed  until  the  end 
of  the  race  is  near.  They  are  willing  to  be  breathless 
at  the  very  last  because  they  are  soon  to  stop  running 
and  catch  their  breath  again.  But  to  get  breathless  at 
the  beginning  of  the  race  means  defeat.  And  what  may 
be  said  about  training  the 
machine  that  does  our 
breathing  for  us  ?  Make  a 
series  of  tests  for  yourself. 

Tests  of  Chest  Capacity. 
Place  one  hand  lightly 
on  your  chest ;  place  the 

Other    On    your    back    be-  MEASURED  BY  THE  DOCTOR 

tween  the  shoulder  blades;  inhale  slowly  until  your 
lungs  are  full,  then  exhale  slowly  until  they  seem  empty. 
While  you  do  this,  notice  that  the  breastbone  rises  and 
that  the  front  and  rear  walls  of  your  chest  are  forced 
gradually  farther  apart. 

While  you  take  another  long  breath  and  send  it  out 
again,  stand  with  your  hands  resting  lightly  on  each  side 
of  the  body  just  over  your  lower  ribs.  Notice  that  it 
is  expansion  sidewise  this  time;  you  also  see  that  the 
capacity  of  your  chest  has  increased  greatly.  It  is  as 
if  you  had  pumped  air  into  an  elastic  bag. 


108        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


WITH  HIS  CHEST  CONTRACTED 


Increasing  the  Chest  Girth.  Take  a  tape  measure  and 
get  the  girth  of  your  chest  after  you  have  exhaled  all 
you  can,  and  again  after  you  have  inhaled  all  you  can. 

Learn  from  these  tests  that 
the  size  of  your  chest  can  be 
increased  and  diminished  at 
will,  and  that  its  size  can 
be  increased  permanently  by 
frequent  exercise  of  this  kind. 
To  prove  this,  measure  your 
chest  to-day;  then  for  two 
months  take  fifteen  deep  full 
breaths  three  times  a  day. 
With  each  breath  expand  your  lungs  as  fully  as  you 
can  without  really  straining  them.  At  the  end  of  the 
two  months  measure  yourself 
again,  and  you  will  find  that 
your  chest  measure  has  in- 
creased. From  this  you  have 
the  right  to  conclude  that 
your  lungs  also  are  larger. 

Structure  of  the  Lungs.  We 
often  talk  of  the  lungs  as  if 
they  were  a  pair  of  big  bags 
tucked  in  under  the  ribs  somewhere,  waiting  to  swell 
out  or  sink  in  according  as  we  use  them.  In  a  way  the 
notion -of  the  bag  is  correct,  except  that  instead  of  two 


WITH  HIS  CHEST  EXPANDED 


TRAINED  AND  UNTRAINED  LUNGS 


109 


bags,  one  on  each  side,  we  must  think  of  thousands  upon 
thousands  of  microscopic  bags,  called  air  sacs.  We  must 
recall  what  we  learned  in  Health  and  Safety,  and  think 
of  these  air  sacs  as  the  most  important  part  of  the 
branching  tubes  of  the  lungs.  We  must  remember  that 
within  the  large  chamber  which  the  ribs  make  we  have 
two  sets  of  these  tubes  ending  in  air  sacs.  Each  set  is 
called  a  lung.  The  heart  lies 
between  the  right  and  left 
lungs  and  is  a  trifle  more  on 
the  left  side  than  on  the  right. 
Work  of  the  Lungs.  For 
the  sake  of  saving  time  and 
space  a  few  facts,  new  and 
old,  must  be  given  under 
numbered  headings.  They 
show  how  the  lungs  help  us 
throughout  our  lives. 

1.  Blood  that  enters  the  lungs  is  so  dark  and  so 
heavily  laden  with  carbon  dioxide  —  although  there 
is  also  some  oxygen  in  it  —  that  we  call  it  impure. 
Blood  that  leaves  the  lungs  is  so  well  loaded  with 
oxygen  that  it  has  gained  a  bright  scarlet  color,  and 
we  call  it  pure,  as  indeed  it  is.    Even  in  pure  arte- 
rial blood,  however,  there  is  some  carbon  dioxide. 

2.  The  lungs  are  at  work  not  because  they  them- 
selves need  air,  but  because  they  serve  as  a  clearing 


TUBES  AND  AIR  SACS  OF  THE 
LUNGS 


110       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

house  in  which  oxygen  and  carbon  dioxide  may 
change  places.  Such  a  central  exchange  is  needed 
because,  as  we  know,  each  smallest  tissue  over  the 
entire  body  is  in  need  of  oxygen  and  must  be  re- 
lieved of  its  carbon  dioxide.  It  is  in  the  lungs  that 
blood  unloads  itself  of  most  of  its  useless  carbon 
dioxide,  loads  itself  up  with  oxygen,  and  streams 
off  to  some  distant  destination.  Breathing,  then,  is 
mainly  for  the  benefit  of  the  tissues  of  the  body, 
not  for  the  sake  of  the  lungs  themselves. 

3.  All  the  blood  of  the  body  comes  to  the  lungs 
and  goes  away  again  once  every  twenty-three  sec- 
onds. While  it  passes  through  the  lungs  it  does 
not  leave  the  capillaries,  but  the  capillaries  them- 
selves are  so  closely  intertwined  with  the  air  sacs 
that  the  two  cannot  be  separated,  and  since  they  lie 
so  close  together,  rapid  exchanges  are  taking  place 
constantly.  Oxygen  mixed  with  the  other  gases  of 
the  air  is  on  one  side  of  the  animal  membrane  of  the 
air  sac ;  carbon  dioxide,  with  a  little  oxygen,  is  in  the 
blood  on  the  other  side  of  the  membrane,  within 
the  capillaries.  And  as  the  gases  are  side  by  side, 
two  of  them  —  the  oxygen  and  the  carbon  dioxide 
—  change  places  without  delay.  Oxygen  enters  the 
blood  from  the  air  sac ;  carbon  dioxide  enters  the  air 
sac  from  the  blood;  the  red-corpuscle  carriers  are 
loaded  with  oxygen  in  the  twinkling  of  an  eye  and 


TRAINED  AND  UNTRAINED  LUNGS 


III 


hasten  off  to  unload  their  cargo  where  it  is  needed. 
In  the  meantime,  however,  the  large  supply  of  car- 
bon dioxide  is  as  unwelcome  in  the  air  sac  as  it 
is  everywhere  else  in  the  body.  It  is  therefore 
expelled  quickly  by 
an  outgoing  breath. 
In  this  way  the  body 
relieves  itself  of  car- 
bon dioxide  by  every 
breath  we  exhale. 
In  view  of  these  three 

important  facts  it  is  quite 

evident  that  large  healthy 

lungs   will   be   invaluable 

to   any   one   who   wishes 

to  take  vigorous  exercise, 

and    that,    on    the    other 

hand,    exercise    itself    is 

the     Very     best     thing    for 

lung  development. 

Inactive  Air  Sacs.  The 
entire  group  of  sacs  should  often  be  compelled  to  ex- 
pand more  fully  than  they  naturally  do  in  the  course 
of  regular  daily  breathing,  and  the  best  way  to  expand 
them  is  not  by  standing  still  and  taking  deep  breaths, 
but  by  using  large  muscles  vigorously,  thus  compelling 
the  lungs  to  work  hard  too. 


HEART  AND  LUNGS  IN  CLOSE 
CONNECTION 

A,  left  lung ;  B,  heart ;  Z>,  tube  through 
which  blood  goes  to  the  lungs  to  be  puri- 
fied ;  £,  windpipe  through  which  air  goes 
to  the  lungs  with  oxygen  for  the  air  sacs 


112        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Many  a  sagging  chest  hides  from  sight  multitudes  of 
inactive  air  sacs  that  have  never  been  expanded  through 
hard  exercise.  Nevertheless,  each  separate  one  would 
have  worked  well  and  would  have  increased  in  size  if 
its  owner  had  compelled  it  to  gain  capacity  and  power 
through  such  hard  breathing  as  comes  from  fast  walk- 
ing, from  running,  jumping,  and  swimming,  or  from  lively 
games  played  out  of  doors. 

Only  by  the  full  breath,  which  is 
broad  as  well  as  deep,  does  much  air 
get  into  the  upper  corners  of  the  lungs, 
and  these  air  sacs,  left  inactive,  yield 
quickest  to  disease  microbes.  Here  it 
GROUPS  OF  AIR  is  that  tuberculosis  most  often  begins 

SACS  its  work. 

Health  and  Exercise.  Fortunately  we  get  exercise 
whether  we  use  our  muscles  in  work  or  play,  and  the 
more  we  enjoy  it  the  better  off  we  are.  Work  in  garden 
and  hayfield,  mowing  the  lawn,  and  hoeing  —  all  are 
good,  provided  the  body  is  not  overtaxed.  If  a  young, 
frail  boy  gets  too  tired,  his  stomach  and  other  organs 
will  not  serve  him  well.  Almost  every  kind  of  play  is 
valuable,  unless  it  overstrains  the  heart  as  hard  rowing- 
races  and  basket-ball  contests  may  do.  The  feeling  of 
utter  exhaustion,  of  being  exceedingly  out  of  breath,  is 
harmful.  It  must  be  avoided.  The  very  best  exercise 
is  that  which  one  gets  in  moderate  walking,  running, 


TRAINED  AND  UNTRAINED  LUNGS 


jumping,  swimming,  riding  horseback,  and  playing  out- 
of-door  games.  By  taking  the  right  sort  of  exercise  we 
sleep  well,  have  a  good  appetite  and  a  clear  brain.  The 
following  rules  will  help : 

1.  Exercise  vigorously  every 
day.  We  cannot  exercise  enough 
in  one  day  to  last  a  week,  any 
more  than  we  can  eat  enough 
in    one    day    to    last    a   week. 
Violent    exercise    should    not 
come  either  just  before  or  just 
after  eating. 

2.  Make  sure  to  give  exer- 
cise not  only  to  arms  and  legs, 
but  especially  to  the  big  mus- 
cles  of   the   chest,   back,   and  AlR  PASSAGES 

i    i  C,  nasal  cavities  ;  Af,  mouth 

abdomen.  cavity;  ^  tongue;  ^  epi. 

The  Breathing  Apparatus.  In  study-   glottis;  G,  glottis,  or  oPen- 

ing  from  the  pharynx  into  the 

mg  our  breathing  apparatus,  recall  trachea;  u,  the  end  of  the 
what  you  learned  about  the  nose  in  softPalate;  °>  ^sophagus 
Health  and  Safety,  and  bear  in  mind  the  following  facts. 
Air  enters  the  lungs  through  tubes  that  begin  with  the 
nose  and  end  in  air  sacs.  From  first  to  last  these  tubes 
are  continuous  and  unbroken,  but  each  part  has  its  own 
name.  Here  they  are ;  each  one  is  most  important  — 
pharynx,  larynx,  trachea,  bronchial  tubes,  bronchioles, 
air  sacs.  Now  take  them  up  for  separate  study. 


114        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

i.  Pharynx.  Both  food  and  air  use  this  entrance 
to  the  body  through  the  mouth.  Open  your  mouth 
wide  before  the  mirror.  See  the  soft  palate  hanging 
downward.  This  is  the  curtain  which  separates  the 
mouth  itself  from  the  pharynx.  Now  look  just 
beyond  and  below  the  palate.  See  two  rounded 
objects,  one  on  each  side  of  the  pharynx.  These 
are  the  tonsils.  When  in  good  order  they  hold 
and  destroy  germs  that  enter  the  body  with  food 
and  air.  When  out  of  order  they  grow  large  and 
inflamed,  being  diseased  by  the  very  germs  they 
have  captured.  When  this  happens  they  do  the 
body  more  harm  than  good,  and  the  doctor  must 
cure  them  or  remove  them.  Nowadays  tonsils 
and  adenoids  are  receiving  close  attention  from  the 
doctors,  because  it  is  known  that  they  are  often 
twin  hindrances  to  the  breathing  apparatus.  An 
adenoid  is  simply  a  growth  of  tissue  far  back  in 
the  nose.  And  just  because  this  growth  is  there, 
it  prevents  air  from  going  freely  to  the  lungs  and 
compels  a  person  to  be  what  is  known  as  a  mouth 
breather.  Whenever  we  see  a  mouth-breathing  child 
who  is  dull  and  forlorn,  unable  to  learn  his  lessons, 
and  discouraged,  we  look  for  adenoids  and  diseased 
tonsils.  Usually  both  are  found,  although  the  follow- 
ing case  of  a  twelve-year-old  boy  in  Cleveland,  Ohio, 
speaks  of  adenoids  alone. 


TRAINED  AND  UNTRAINED  LUNGS  115 

May  i,  1907.  Hearing  very  defective;  hears  watch  at  six  inches. 
Sleeps  badly,  snores,  appetite  poor,  frequent  colds,  restless,  in- 
attentive, stupid,  eyesight  defective,  frequent  headaches,  adenoids. 

May  3,  1907.  Adenoids  removed.  Eyeglasses  secured  two 
weeks  later. 

June  10,  1907.  Hears  watch  at  four  feet,  breathes  freely 
through  nose,  sleeps  soundly,  never  snores,  appetite  good,  head- 
aches have  ceased.  Has  been  transformed  into  a  calm,  bright, 
attentive,  and  well-behaved  pupil. 

Thousands  of  other  boys  and  girls  have  had  the 
same  happy  experience ;  so  many,  indeed,  that  now- 
adays it  is  quite  the  expected  thing  for  a  doctor  to 
examine  any  ailing  child  for  adenoids  and  swollen 
tonsils  and  to  remove  them  if  found.  It  is  a  simple 
operation  and  quickly  over. 

In  the  pharynx,  with  the  tonsils,  is  a  device 
which  saves  us  from  choking  when  we  eat.  This 
is  the  glottis.  It  is  an  opening  from  the  pharynx 
into  the  windpipe.  The  cover  to  this  opening  is 
called  the  epiglottis.  Whenever  we  swallow,  this 
traplike  cover  shuts  itself  down  over  the  glottis 
and  prevents  food  from  getting  into  the  windpipe 
where  air  alone  should  go.  Because  the  epiglottis 
is  down,  food  slides  unhindered  through  the  food 
tube  to  the  stomach.  When  a  person  chokes,  it  is 
because  the  epiglottis  has  been  slightly  raised  and 
bits  of  food  have  slipped  into  the  windpipe.  Joined 
to  the  pharynx  is  the  next-named  part,  the  larynx. 


Il6        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

2.  The  larynx,  or  voice  box.  This  is  a  cavity 
inclosed  by  walls  of  cartilage,1  and  it  lies  directly 
behind  the  Adam's  apple.  Within  this  cavity  are 
stretched  bands  of  tissue  called  vocal  cords.  By 
using  these  cords  we  produce  sounds,  have  a  voice, 
and  are  enabled  to  speak  and  sing.  We  may  also 
train  and  control  the  vocal  cords  and  to  a  large 
extent  may  have  sweet  voices  or  harsh  voices  as  we 
wish.  Inflamed  vocal  cords  will  produce  hoarseness. 
To  get  pleasant  sounds  from  your  vocal  cords,  place 
the  voice  in  the  front  of  the  mouth.  You  can  do  it 
as  follows :  First  whisper  the  sentence,  "  I  will  speak 
with  my  lips  and  the  tip  of  my  tongue."  In  a  whis- 
per we  always  use  the  front  of  the  mouth.  Now 
vocalize  this  whisper,  that  is,  give  to  the  whisper, 
sound.  You  will  find  that  you  have  kept  your  voice 
in  the  front  of  your  mouth.  It  is  easy  to  injure  the 
vocal  organs  by  placing  the  voice  too  deep  in  the 
throat.  Many  a  public  speaker  does  this.  While 
the  voice  is  changing,  one  may  yell  so  furiously  at 
a  ball  game  as  to  strain  the  vocal  cords  beyond 
repair.  The  power  to  utter  sweet  sounds  is  then 
gone  forever.  Singers  are  always  careful  to  guard 
their  vocal  cords  from  severe  strain  of  any  sort  and 
from  colds  which  inflame  the  membranes.  Even  we 
who  are  not  singers  should  be  careful  too. 

1  Something  like  stiff  gristle. 


TRAINED  AND  UNTRAINED  LUNGS  117 

3.  The  trachea  is  the  windpipe.    It  extends  from 
the  larynx  to  the  lungs,  where  it  divides  into  two 
branches.   These  branches  are  the  bronchial  tubes. 

4.  The  bronchial  tubes.   When  we  take  cold  and 
the  lining  of  these  tubes  becomes  inflamed,  we  have 
bronchitis.    Each  of  the  bronchial  tubes  divides  and 
subdivides  into  ever  smaller  branches  and  twigs,  un- 
til they  end  in  what  are  known  as  the  bronchioles. 

5.  The  bronchioles.  These  bronchioles  themselves 
end  in  the  smallest  of  pouches,  in  which  are  our 
often-mentioned  air  sacs. 

6.  Air  sacs  are   tiny  pits   on  the    sides   of   the 
pouches.    Each  separate  sac  is  surrounded  by  the 
finest  possible  network  of  capillaries,  and  the  lining 
of  the  sacs  is  so  thin  that  it  would  take  twenty- 
five  hundred  layers  of  it  to  make  one  inch  in  thick- 
ness.   It  is  within  these  sacs  that  the  blood  in  the 
capillaries  turns  from  dark  red  to  bright  red,  from 
impure    venous    blood    to    purified    arterial    blood. 
The  outside   covering   of   the   lungs  is  called  the 
pleura.    When  it  is  inflamed  we  have  pleurisy. 

Clean  Air  for  the  Lungs.  From  nose  to  lungs  the 
entire  lining  of  the  breathing  apparatus  is  a  damp 
mucous  membrane.  It  catches  and  holds  microbes  and 
bits  of  dust  that  may  be  in  the  air  we  breathe.  More- 
over, as  described  in  Health  and  Safety,  thousands  upon 
thousands  of  threadlike  cilia  are  on  the  lining  of  the 


Il8        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

nose  and  of  the  largest  tubes  of  the  lungs.  Whether  we 
are  awake  or  asleep,  they  move  ceaselessly  like  velvet 
paddles,  always  sweeping  mucus  upward  towards  the 
mouth,  and  in  this  mucus  are  the  captured  microbes 
and  bits  of  dust  which  must  be  kept  from  the  air  sacs 
and  thrown  out  of  the  body.  Thus  we  see  that  all  the. 
breathing  we  do,  and  the  entire  breathing  apparatus,  is 
for  the  immediate  purpose  of  supplying  the  lungs  with 
air  —  clean  air  if  possible.  This  air  holds  oxygen  for  the 
tissues  and  exchanges  it  for  carbon  dioxide  from  the 
tissues.  Without  the  exchange  we  should  promptly  die, 
and  the  more  complete  the  exchange  the  better  we 
live.  For  this  reason,  then,  we  make  the  most  of  our 
breathing  apparatus.  We  stand  straight,  walk  with  chest 
expanded,  take  deep  breaths  of  pure  air  through  the 
nose  with  the  mouth  closed,  and  give  strict  attention 
to  the  increase  of  our  lung  capacity.  It  is  for  each  one 
of  us  to  decide  whether  the  air  we  breathe  shall  be  as 
pure  by  night  as  by  day,  and  whether  it  is  always  as 
pure  as  it  should  be. 

Value  of  Moist  Air.  In  addition  to  all  else,  we  should 
take  particular  pains  to  supply  our  homes  with  fresh  air 
that  is  moist.  (Review  the  directions  for  ventilation  given 
in  Health  and  Safety?)  When  furnaces,  stoves,  or  steam- 
pipes  warm  us  in  winter,  indoor  air  gets  so  dry  that 
the  delicate  tissues  of  the  nose  and  lungs  suffer.  Several 
devices  help.  For  a  hot-air  furnace  keep  the  water  in 


TRAINED  AND  UNTRAINED  LUNGS  119 

the  pan  of  the  furnace  always  full.  Evaporation  of  this 
water  will  moisten  the  air  and  reach  the  entire  house. 
For  steam-heated  houses,  pans  are  made  to  be  attached 
to  the  radiators.  These  should  be  kept  filled  with  water. 
It  evaporates  and  moistens  the  air.  Try  any  device  that 
will  send  moisture  into  the  overdry  winter  air  of  our 
homes.  As  a  rule,  out-of-door  air  is  moist  enough  and 
desirable  in  every  way.  For  this  reason,  get  all  of  it 
you  can.  Be  out  of  doors  much  by  day,  and  sleep  on 
a  sleeping  porch  or  with  windows  open  at  night. 

Getting  an  All-round  Development.  With  the  facts 
about  his  breathing  apparatus  before  him,  let  the  flat- 
chested  person  set  about  his  own  improvement.  Let 
him  know  that  the  best-developed  leg  muscles  are  of 
little  use  for  running  unless  heart  and  lungs  are  able  to 
do  their  share  of  the  work,  for,  as  some  one  has  said, 
"  We  run  as  much  with  our  -lungs  as  with  our  legs." 
We  next  study  foods,  the  source  of  all  our  energy. 

QUESTIONS 

1.  If  you  were  ever  thoroughly  out  of  breath,  describe  the  sensa- 
tions you  had.  2.  In  a  hard  run,  what  happens  to  the  tissues  of  the 
body  ?  3.  What  gas  is  produced  by  tissues  as  they  work  ?  4.  What 
gas  do  they  greatly  need?  5.  Through  what  stream  do  the  tissues 
get  rid  of  their  carbon  dioxide  and  receive  their  oxygen  ?  6.  Why  does 
the  blood  stream  need  to  flow  fast?  7.  What  three  things  combine 
to  bring  about  breathlessness  ?  8.  What  can  be  done  to  strengthen 
the  heart  ?  9.  When  does  carbon  dioxide  form  fastest  ?  10.  When  do 
we  use  the  most  oxygen?  11.  When  does  a  man  give  off  the  least 


120        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

carbon  dioxide  and  call  for  the  least  oxygen  ?  12.  Why  is  the  heart  over- 
taxed when  we  run  hard?  13.  What  does  a  trained  athlete  learn  about 
managing  the  work  of  the  heart  and  the  lungs  ?  14.  During  exercise, 
which  muscles  give  a  hurry  call  for  oxygen?  15.  Which  two  organs 
of  the  body  need  to  be  trained  in  their  relation  to  each  other? 

16.  Mention  tests  which  show  that  lung  size  can  be  increased. 
17.  How  many  lungs  have  we?  18.  Where  are  they?  19.  What  is 
an  air  sac?  20.  WThen  is  blood  called  impure?  21.  When  is  blood 
pure?  22.  What  is  the  condition  of  the  blood  when  it  enters  the 
lungs  ?  when  it  leaves  the  lungs  ?  23.  In  what  way  are  the  lungs  a 
storehouse?  24.  What  exchange  goes  on  in  the  air  sacs?  25.  Wrhere 
do  the  red  corpuscles  carry  the  oxygen?  26.  Do  we  breathe  for  the 
benefit  of  the  lungs  or  of  the  tissues?  27.  How  long  does  it  take 
blood  to  make  the  circuit  of  the  body  ?  28.  Describe  the  way  in  which 
oxygen  and  carbon  dioxide  change  places  in  the  lungs.  29.  Why  are 
large  lungs  an  advantage  to  the  body  ?  30.  How  may  their  size  be 
increased?  31.  What  are  the  best  kinds  of  exercise  for  the  lungs? 
32.  What  danger  comes  from  inactive  air  sacs  ?  33.  Where  does  tuber- 
culosis most  often  begin?  34.  Why  should  breathing 'be  done  through 
the  nose  and  not  through  the  mouth  ?  35.  Why  should  air  be  well 
cleaned  before  it  enters  the  air  sacs  ? 

36.  Mention  the  names  of  different  parts  of  our  breathing  apparatus. 
37.  'What  can  be  seen  in  the  pharynx?  38.  Of  what  use  are  the 
tonsils  ?  39.  When  diseased  what  should  be  done  to  them  ?  40.  What 
are  adenoids?  41.  How  do  they  hinder  breathing?  42.  Describe  the 
condition  of  the  Cleveland  schoolboy  before  and  after  his  adenoids  were 
removed.  43.  Describe  the  glottis  and  the  epiglottis.  44.  Where  is  the 
larynx?  45.  What  cords  are  in  it?  46.  What  can  be  done  in  training 
the  vocal  cords?  47.  Give  another  name  for  the  windpipe.  48.  What 
happens  when  the  bronchial  tubes  are  inflamed  ?  49.  What  is  the  spe- 
cial work  of  the  air  sacs  ?  50.  What  kind  of  substance  lines  the  entire 
breathing  apparatus  ?  51.  Of  what  use  is  it  ?  52.  Where  and  what  are 
the  cilia  ?  53.  What  is  pleurisy  ? 


CHAPTER  IX 
EATING  AND  OUR  FOOD  SUPPLY 

Experiments  in  Eating.  In  1903  Professor  Chittenden 
of  Yale  University  conducted  some  scientific  experi- 
ments on  a  rather  large  scale.  He  began  with  himself, 
enlisted  the  help  of  others,  and  finally  had  in  hand 


SOLDIERS  WHO  SERVED  ON  THE  EATING  EXPERIMENT 

thirteen  soldiers  whose    ages    ranged   from  twenty-two 
years  and  six  months  to  forty-three  years. 

Close  attention  was  given  to  the  men  in  several  ways. 
At  quarter  of  seven  each  morning  they  were  weighed. 
This  was  necessary,  for  they  were  eating  about  half  as 
much  meat  as  usual,  with  somewhat  less  of  other  kinds 
of  food,  and  it  was  important  to  know  each  day  whether 
they  were  gaining  or  losing  by  the  new  diet. 


122        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

At  seven  came  breakfast.  Here  each  separate  kind  of 
food  was  weighed  before  it  was  given  to  the  man  who 
was  to  eat  it.  What  he  did  not  eat  was  also  weighed, 
that  Dr.  Chittenden  might  know  just  how  much  had 
been  used.  Moreover,  these  men  were  allowed  to  eat 


TEN  OF  THE  SOLDIERS  TAKING  EXERCISE  IN  THE  GYMNASIUM 

only  such  food  as  was  served  to  them.  All  eating 
between  meals  was  strictly  forbidden. 

Aside  from  this  close  care  about  their  food,  the  men 
were  not  hampered  in  many  ways.  They  went  to  the 
theater  sometimes,  worked  in  the  Yale  gymnasium  an 
hour  a  day,  had  regular  drill  under  their  officers,  and 
went  to  bed  at  ten  o'clock. 

When  they  left  New  Haven  six  months  later,  Dr.  An- 
derson, director  of  the  gymnasium,  wrote  as  follows : 


EATING  AND  OUR  FOOD  SUPPLY  123 

The  men  were  not  above  the  average  standard  physically  when  they 
began  their  work,  this  standard  being  set  by  applicants  for  positions  as 
firemen  and  policemen,  not  by  college  students.  At  the  end  of  the 
training  they  were  much  above  the  same  standard,  while  the  strength 
tests  were  far  greater  than  the  averages  made  by  college  men. 

These  tests  did  not  settle  all  food  questions,  but  they 
seemed  to  make  it  clear  that  even  soldiers  may  gain 
strength  on  much  less  meat  than  they  have  been  in 
the  habit  of  eating.  As  for  the  rest  of  us,  science  has 
proved  that  the  welfare  of  the  body  is  closely  related  to 
the  food  we  give  it,  that  the  kind  of  food  makes  a  dif- 
ference in  the  quality  of  the  work,  that  he  who  works 
little  harms  himself  when  he  eats  much,  and  that 
growing  children  need  much  more  food  than  their 
inactive  elders. 

What  Food  does  for  the  Body.  All  scientists  agree  that 
food  does  two  things  for  the  body : 

1.  Food  builds  tissue;  that  is,  it  makes  the  body 
.grow  by  adding  fresh  tissue  for   the   building   of 
muscle,  bone,  blood,  brain,  etc.,  and  it  makes  the 
body  new  by  replacing  all  tissues  as  fast  as  they 
wear  out. 

2.  Food  produces  energy  by  which  the  body  does 
the  work  of  muscle,  bone,  brain,  and  beating  heart, 
while  at  the  same  time  it  keeps  itself  warm.    Food 
so  used  is  the   fuel  for   our   engines.    No  engine 
runs  well  when  fuel  is  lacking. 


124       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

We  eat,  then,  for  the  purpose  of  meeting  one  or  the 
other  of  these  two  great  demands  of  the  body,  and  our 
success  or  failure  in  life  may  easily  turn  on  what  we 
know  or  do  not  know  about  the  value  of  our  food. 

The  Five  Food  Substances.  When  Professor  Chittenden 
planned  meals  for  his  soldiers,  his  main  thought  was  not 
as  to  whether  he  should  give  them  beefsteak,  mutton 
chops,  fish,  eggs,  bread,  or  vegetables,  but  whether  or 
not  he  was  giving  them  the  right  proportions  of  certain 
substances  which  living  bodies  need  if  they  are  to  do 
good  work.  These  substances  are  known  as  proteids, 
carbohydrates,  fats,  water,  and  mineral  matter.  They  are 
the  general  materials  out  of  which  our  bodies  are  built, 
and  they  are  so  closely  united  with  each  other  in  blood 
and  tissue  that  only  the  chemist  can  separate  them. 
The  next  page  gives  a  table  made  up  from  reports  pre- 
pared by  the  United  States  Department  of  Agriculture. 
It  shows  how  materials  which  the  body  must  have  are 
distributed  in  some  of  the  foods  we  eat.  In  this  table 
the  single  word  "  carbohydrate "  is  used  instead  of  the 
two  words  "sugar"  and  "  starch."1 


1  Notice  that  some  of  the  substances  in  the  table  are  moist,  while  others  are 
dry ;  and  remember  that  before  many  of  the  dry  foods  are  eaten,  a  great  deal  of 
water  is  added  to  them.  This  is  notably  true  of  the  cereals,  of  rice,  and  of  flour. 
For  example,  what  we  buy  as  one  pound  of  rice  at  the  grocer's  comes  to  the  table 
as  nearly  four  pounds  of  moist  food.  The  chief  difference  between  dry  and  moist 
foods  is  simply  that  when  we  eat  dry  foods  we  take  less  of  the  food  and  more 
water.  Vegetables,  fruit,  meat,  milk,  eggs,  puddings,  and  pies  are  moist  foods. 
See  the  quantity  of  water  in  them  which  the  table  shows. 


EATING  AND  OUR  FOOD  SUPPLY  125 

FOOD  SUBSTANCES  AS  FOUND  IN  DIFFERENT  ARTICLES  OF  DIET1 


illlllillllllillllllilllli 

PROTEID      CARBOHYDRATE 


FAT 


WAT  E  R       M I  NEPAL  MATTER 


Bread    .... 

Wheat  flour  .  . 
Oatmeal  .  .  . 

Rice 

Green  peas  .  . 
Potatoes  .  .  . 

Milk 

Cheese  .... 
Roast  beef  .  . 
Leg  of  mutton  . 

Veal 

Chicken  .  .  . 
Canned  salmon  . 

Egg 

Butter  .... 
Fresh  oysters  . 
Macaroni  .  .  . 
Oyster  crackers  . 
Gingerbread  .  . 
Sponge  cake  .  . 
Apple  pie  .  .  . 
Squash  pie  .  . 
Tapioca  pudding 
Fresh  asparagus . 
Dried  beans  .  . 
Fresh  cabbage  . 
Green  corn  .  . 
Dried  peas  .  . 
Fresh  tomatoes  . 
Bananas  .  .  . 
Fresh  cranberries 
Dried  prunes .  . 
Almonds  .  .  . 
Peanuts  .  .  . 
Brazil  nuts  .  . 
Soft-shell  walnuts 


I      '      .1 
20         30 


I       '       | 
4O        5O 


60 


r 

70 


1  These  tables  are  made  up  from  facts  supplied  by  Bulletin  28  (revised  edition) 
of  the  United  States  Department  of  Agriculture. 


126        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Studying  the  Cost  of  Foods.  Study  the  food  chart  and 
decide  which  articles  cost  most  Into  the  expensive 
group  will  go  all  the  meats.  Dried  vegetables  and  maca- 
roni will  be  in  the  other  group.  Notice  the  amount  of 
proteid  and  of  carbohydrate  in  the  different  foods.  For 
example,  compare  dried  beans  and  roast  beef.  Take 
macaroni,  add  cheese  to  it,  and  we  have  an  admirable, 
inexpensive  food.  It  contains  all  the  proteid  we  need, 
with  abundance  of  carbohydrate  and  fat.  In  dried  beans 
and  dried  peas  we  also  have  all  the  proteid  we  need,  and 
carbohydrate  too.  So  far  as  the  food  supply  of  the  body 
is  concerned,  these  inexpensive  foods  do  just  as  much 
for  us  as  expensive  meats.  Besides,  they  have  the  ad- 
vantage of  being  free  from  damaging  microbes  —  which 
is  more  than  can  be  said  of  meats.  Indeed,  meat  harbors 
so  many  microbes  that  decay  easily  sets  in  both  before 
and  after  it  is  eaten. 

Perhaps  we  wonder  why  Professor  Chittenden  took 
such  care  about  his  food  substances,  and  why  we  our- 
selves should  give  so  much  time  to  the  study  of  the 
same  subject.  The  facts  answer  these  questions. 

Plants  as  Food  Producers.  Our  entire  food  supply  comes 
from  living  and  growing  things,  that  is,  from  plants  and 
animals.  Plants  gather  food  for  themselves  from  earth, 
air,  and  water.  Each  plant  is  therefore  a  producer,  a 
food  factory,  while  at  the  same  time  it  is  a  storehouse  of 
energy;  Each  takes  carbon  dioxide  from  the  air,  water 


EATING  AND  OUR  FOOD  SUPPLY  127 

from  the  earth,  sunlight  from  the  skies,  and  by  its  mar- 
velous power  it  combines  these  things  that  are  not  foods 
into  the  foodstuff  starch.  We  find  starch  in  fruits,  vege- 
tables, and  grains.  It  is  more  abundant  on  the  earth 
than  any  other  food,  and  we  speak  of  it  as  if  it  were  a 
simple  substance.  Instead,  the  entire  starch  supply  of 
the  world  is  composed  of  unnumbered  small  granules,  — 
easily  seen  under  the  microscope,  —  and  each  separate 
granule  is  wrapped  within  its  own  tiny  cellulose  enve- 
lope. To  a  large  extent  all  plants  are  made  up  of  starch 
and  cellulose.  When  starch  substances  are  cooked,  the 
cellulose  envelope  breaks  up.  This  lets  the  starch  out, 
and  it  becomes  digestible  food.  It  is,  indeed,  for  the  sake 
of  breaking  up  the  envelope  that  we  cook  our  vegetables 
and  our  grains  so  carefully.  Starch  is  a  carbohydrate, 
so  also  is  sugar,  which  is  very  much  like  starch  in  its 
chemical  make-up.  We  find  starch  in  green  fruit.  This 
turns  to  sugar  as  the  fruit  ripens,  and  the  fruit  is  then 
sweet.  Some  vegetables  also  contain  sugar  as  well  as 
starch. 

Carbohydrate  for  Energy.  The  carbohydrates  starch 
and  sugar  are  the  substances  which  —  with  fat  —  give 
the  body  most  of  its  energy.  They  do  'no  building  of 
bone,  brain,  or  muscle,  but  act  as  fuel  for  the  furnace  of 
the  body,  giving  power  to  muscles,  bones,  heart,  brain, 
and  every  other  organ.  If  we  eat  more  carbohydrate 
than  we  need  at  the  time,  the  body  stores  part  of  it  up 


128        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


as  fat  and  sends  the  rest  of  it  from  the  lungs  as  carbon 
dioxide,  or  from  the  skin  and  kidneys  as  water.  No  part 
of  this  waste  is  left  in  the  blood.  Carbohydrate  stored 

up  as  fat  is  often  as  useful 
to  the  body  in  time  of  need 
as  money  in  the  bank  is  to 
a  man  who  lacks  cash  and 
needs  to  make  a  purchase. 

The  Proteids.  An  animal 
is  not  a  genuine  food  pro- 
ducer; that  is,  it  does  not 
manufacture  food  from  water, 
earth,  sunlight,  and  air  as 
plants  do.  It  is  primarily  a 
consumer  of  food.  So  true 
is  this  that  if  animals  were 
compelled  to  use  each  other 
as  food,  leaving  plant  foods 
untouched,  the  animal  life  of 
the  world  would  soon  vanish 
altogether. 

Little  carbohydrate  appears,  because  Animal     proteid     is     found 

most  of  the  sugar  and  'starch  which  we     abundantly  in  all  animal  foods 

eat  is  used  up  in  the  shape  of  heat  and 

muscular  work  and  sent  from  the  body      in  milk,  cheese,  lean  meat, 

as  carbon  dioxide.  When  we  eat  more  i  •    i              r.    i             i                  r>i 

carbohydrate  than  we  need,  the  sur-  chickens,  fish,  and  CggS.    Plant 

plus  is  stored  up  as  fat.  The  diagram  proteid  is  for  the  most  part 
shows  that  the  body  keeps  a  good  deal  ... 

of  this  on  hand  ready  for  use  found    in   peas,    beans,   lentils, 


Profeids 


Carbohydrates 


THIS  SHOWS  WHAT   PROPORTION  OF 

THE  HUMAN  BODY  is  COMPOSED  OF 

EACH  SUBSTANCE  WHICH  WE  TAKE 

AS  FOOD 


EATING  AND  OUR  FOOD  SUPPLY  129 

and  nuts.  Grains  also  contain  proteid,  and  there  is  a  little 
of  it  in  most  vegetables.  Study  the  table  for  interesting 
items  about  the  proportions  found  in  different  foods. 
'  Proteid  for  Tissue  Building.  Proteid  —  whether  from 
plant  or  from  animal  —  is  the  substance  which  the  body 
uses  for  building  up  its  tissues.  When  a  child  is  grow- 
ing, proteid  supplies  him  with  material  for  longer  bones, 
larger  muscles,  bigger  brain,  etc.  When  a  muscle  is 
worn  down  through  exercise,  proteid  is  used  to  build 
it  up  again.1 

If  we  eat  more  proteid  than  we  need,  the  left-over 
part  will  not  be  stored  up  by  the  body  as  is  the  case 
with  left-over  carbohydrate.  Instead,  it  has  to  be  worked 
over  by  the  liver  and  sent  out  of  the  body  through  the 
kidneys.  By  constantly  eating  too  much  proteid,  some 
people  give  the  liver  and  kidneys  more  work  than  they 
can  do.  This  is  made  plain  in  Chapter  XL  We  there 
learn  that  proteid  waste  in  the  blood  stream  is  even  more 
harmful  to  the  body  than  clinkers  are  to  the  furnace. 

The  Fats.  Animal  fat  comes  in  the  shape  of  butter, 
lard,  and  suet.  Vegetable  fat  comes  as  oil  from  nuts, 
from  fruit  like  the  olive,  and  from  cotton  seed. 

The  Minerals.  The  body  gets  part  of  its  needed  min- 
eral matter  from  table  salt,  celery,  lettuce,  and  spinach, 
all  of  which  are  valuable  to  us.  When  too  much  salt  is 
used  it  is  harmful. 

1  Since  there  is  nitrogen  in  proteid,  it  is  sometimes  called  nitrogenous  food. 


130       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Need  of  Drinking  Water.  Drink  at  mealtime  if  you 
wish,  but  never  wash  down  a  mouthful  of  half-chewed 
food.  Avoid  ice-cold  water,  because  it  chills  the  stomach 
and  delays  digestion.  If  digestion  is  delayed,  fermenta- 
tion is  apt  to  set  in,  and  this  means  indigestion.  Drink 
six  glasses  (that  is,  three  pints)  of  water  every  twenty- 
four  hours.  The  body  needs  this  for  several  reasons. 

1.  It   flushes   the   system,   dilutes   harmful    sub- 
stances, and  helps  keep  the  liver  and  the  kidneys 
in  good  condition. 

2.  Over  half  the  substance  of  our  bodies  is  noth- 
ing but  water,  and  every  day  the   body  sends  off 
about  three  pints  of  it  through  the  sweat  glands 
and  the  kidneys.    If  this  amount  is  not  replaced, 
we  are  not  so  well  off. 

Rules  for  Right  Eating.  In  view  of  all  these  facts,  eat- 
ing begins  to  look  like  a  pretty  solemn  matter,  and  we 
ask  ourselves  if  we  must  be  always  thinking  about 
carbohydrates,  proteids,  and  fats  and  of  the  quantity  of 
each  which  we  are  eating.  Certainly  not.  The  one  sen- 
sible way  is  to  remember  what  the  food  substances  are 
and  to  eat  meat  but  once  a  day.  Even  for  growing 
children  this  is  quite  often  enough;  for  ailing  old  folks, 
whose  bodies  do  little  tissue  building,  it  is  often  too 
much.  Be  on  the  safe  side,  therefore,  and  be  sparing 
of  meat.  Eat  vegetables  and  fruit  liberally,  however. 
But  in  doing  this  bear  in  mind  the  laws  of  proper 


EATING  AND  OUR  FOOD  SUPPLY  131 

eating l  —  thoroughness  of  mastication,  regularity  of  meal- 
time, no  eating  between  meals,  save  of  such  fruit  as 
oranges,  and  no  "stuffing"  even  at  mealtime.  Eat  until 
fully  satisfied  of  such  nourishing  foods  as  have  been  pre- 
pared, then  stop.  To  be  hungry  means  that  the  cells  of 
the  body  are  calling  for  food-fuel.  To  feel  this  hunger 
is  a  good  sign,  and  it  should  be  satisfied. 

Many  people  abuse  their  digestive  apparatus  until  at 
last  it  rebels.  For  the  help  of  such  sufferers  careful 
charts  have  been  prepared.  These  show  how  much  food 
of  different  kinds  should  be  used  each  day.  Thus,  by 
carefully  weighing  and  measuring  the  amounts  of  pro- 
teid,  carbohydrate,  and  fat  that  they  eat,  afflicted  people 
are  sometimes  able  to  get  relief.  Better  far  not  to  reach 
the  point  where  such  care  is  needed.  The  truth  is  that 
the  entire  digestive  apparatus  does  its  best  work  when 
there  is  no  anxiety  about  the  food  that  is  being  eaten. 
The  best  plan,  therefore,  is  to  remember  the  great 
general  laws  about  proteids,  carbohydrates,  and  fats, 
to  eat  some  of  each  every  day,  to  obey  all  the  laws  of 
careful  eating,  and  to  give  no  further  worrying  thought 
to  the  matter. 

Balanced  Menus.  When  Professor  Chittenden  selected 
beans,  cheese,  or  eggs  for  his  men,  he  gave  them  little, 
if  any,  meat.  As  best  she  can,  every  housekeeper 
should  do  for  her  family  what  Professor  Chittenden  did 

1  As  given  in  Health  and  Safety. 


132        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

for  his  soldiers.  She  should  supply  well-balanced  meals. 
This  means  that  she  should  make  wise  combinations 
of  foods  containing  proteid,  carbohydrate,  and  fat.  She 
should  not  serve  at  the  same  meal  too  many  kinds 
of  food  that  contain  the  same  substance.  Compare  the 
two  columns  of  menus  given.  Decide  why  the  left- 
hand  ones  are  desirable,  the  right-hand  ones  undesirable. 
Study  the  food  table  and  make  up  menus  of  your  own. 
Put  into  each  one  some  proteid,  some  fat  and  mineral 
matter,  and  much  carbohydrate.  Those  who  study  food 
facts  believe  we  should  eat  fully  five  times  as  much 
carbohydrate  as  proteid. 

Food  for  Bulk.  In  this  connection  it  should  be  stated 
that  food  is  needed  not  for  nourishment  alone  but  for 
bulk  as  well.  Were  it  not  for  this,  we  might  be  content 
to  have  our  food  condensed  into  small  pellets  and 
swallowed  quickly  with  a  mouthful  of  water.  But  the 
stomach  and  the  long  food  tube  need  to  exercise  them- 
selves on  food  that  has  bulk  to  it.  Vegetables  and  fruit 
are  especially  useful  for  this  purpose  because  of  their  bits 
of  cellulose  tissue,  which  make  bulk  and  pass  along 
through  the  body  without  being  digested.  Graham 
flour  and  grain  with  the  hull  on  are  valuable  for  the 
same  reason. 

Vegetarians.  Multitudes  of  people  know  that  they  can 
get  all  the  proteid  they  need  in  other  foods  than  meat. 
When  they  eat  no  meat  they  are  called  vegetarians.  The 


EATING  AND  OUR  FOOD  SUPPLY 


133 


HEALTHFUL 

Breakfast  i 

Baked  apples 

Cereal  and  cream 

Toasted  whole-wheat 

bread 

Breakfast  2 

Oranges,  prunes,  or 

other  fruit 
Boiled  hominy 
Graham  gems 


THE  REASON  WHY 
Breakfast.  This  meal  should  be  light  and 
easily  digested.  The  hardest  work  of  the  day 
comes  in  the  forenoon,  and  it  is  a  mistake  to 
work  hard  after  a  hearty  meal.  In  the  health- 
ful breakfasts  few  articles  are  provided.  In 
the  unhealthful  breakfasts  there  is  too  much. 
Then,  too,  fried  things  always  digest  slowly. 
Coffee  is  objectionable.  If  you  wish  some- 
thing hot,  use  a  cereal  drink. 


UNHEALTHFUL 

Breakfast  i 

Cereal,  cream  and  sugar 

Fried  eggs  and  bacon 

Waffles  and  sirup 

Coffee 

Breakfast  2 
Sausage,  fried  potatoes 

Griddlecakes 
Hot  rolls        Coffee 


Luncheon  i 

Scalloped  corn 

Cottage-cheese  salad 

Graham  bread 

Pineapple  sauce 

Wafers 

Luncheon  2 

Macaroni  and  cheese 

Baked  tomatoes 

Lettuce,  French 

dressing 
Fig  tapioca,  whipped 


Luncheon.  In  the  healthful  luncheons  we 
have  cheese  instead  of  meat  for  the  proteid. 
Corn  and  macaroni  supply  carbohydrate. 
Lettuce  leaves  give  bulk ;  so  also  does  the 
coarse  part  of  graham  bread.  In  the  unhealth- 
ful luncheons  there  is  too  little  carbohydrate. 
As  a  result,  too  much  proteid  will  be  eaten. 
Pickles  are  indigestible.  It  takes  four  hours 
to  digest  ham.  Doughnuts  are  objectionable 
because  they  are  fried  in  deep  fat.  That  which 
digests  slowly  is  apt  to  ferment  in  the 
stomach  and  produce  gas.  Tea  contains 
tannin  and  the  poison  theine. 


Luncheon  i 
Fish  chowder 

Cold  meat 

String  beans 

Baked  apples 

Tea 

Luncheon  2 
Minced  ham  on  toast 

Pickles 
Doughnuts         Coffee 


Dinner  i 
Tomato  soup 

Fish  or 

Leg  of  lamb 

Baked  potatoes 

Creamed  carrots 

Fruit  gelatin 

Dinner  2 

Vegetable  soup 

Roast  chicken 

Browned  potatoes 

Cauliflower 

Cranberry  jelly 

Fruit  salad 

Prune  whip 


Dinner.  Look  at  the  unhealthful  dinners. 
Notice  that  they  have  proteid  in  oysters, 
in  soup,  roast,  vegetables,  salad,  mince  pie, 
and  cheese.  Coffee  and  pickles  are  bad. 
There  is  far  too  much  proteid  and  far  too 
little  carbohydrate  in  these  unhealthful  din- 
ner menus.  The  healthful  dinners  have 
soup  with  no  proteid  ;  potatoes  baked,  which 
is  the  best  way ;  almost  no  proteid  in  the  vege- 
tables ;  no  proteid  in  the  salad,  very  little  of  it 
in  the  desserts.  These  dinners  are  well  bal- 
anced. When  there  are  several  courses  to  a 
meal,  and  especially  when  meat  is  provided, 
make  sure  to  have  light  soups,  salads  and  des- 
serts, and  serve  vegetables  that  are  not  rich 
in  proteids.  Raw  oysters  should  not  be  eaten 
unless  we  know  where  they  come  from.  They 
often  live  in  water  spoiled  by  sewage  and  by 
typhoid  microbes.  Many  people  have  taken 
typhoid  from  contaminated  oysters. 


Dinner  i 

Bean  soup 

Leg  of  lamb 

Mashed  potatoes 

Peas 

Spiced  pickles 

Suet  pudding 

Coffee 

Dinner  2 
Raw  oysters 
Split-pea  soup 

Roast  beef 
Mashed  potatoes 

Lima  beans 

Fruit-and-nut  salad 

Mince  pie          Cheese 

Coffee 


THESE  TEETH  SHOULD 
HAVE  BEEN  STRAIGHTENED 


134        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

millions  of  people  in  India,  China,  and  Japan  live  mostly 

on  rice,  with  its  seventy-nine  per  cent  of  carbohydrate. 

The  Teeth.  Whatever  we  eat,  teeth 
do  the  chewing  and  must  be  kept 
in  order.  These  bits  of  bone  in 
the  mouth  are  covered  with  enamel 
—  hard,  white,  brittle,  and  easily 
cracked.  Breaking  nuts,  opening  a 
knife,  or  seizing  nails  and  other  hard 
substances  with  the  teeth  may  crack 
the  enamel,  and  once  damaged  it 
will  never  mend  itself.  Instead,  mi- 
crobes will  find  their  way  through 

it.    After  this  they  will  work  their  way  to  the  central 

pulp  of  the  tooth,  with  its  small 

blood    vessels    and    nerves.     And 

when  microbes  reach  tooth  nerves 

we  have  the  toothache  —  jumping 

toothache,  generally.    Microbes  are 

in   fact   the    worst   enemies    teeth 

have.    They  live  and   multiply  on 

bits  of  food  between  the  teeth  and 

on  the  gums.    As  they  work  their 

way  through  the  enamel,  we  say  the 

tooth  is  decaying,  as  indeed  it  is. 

To  get  rid   of  microbes  and  prevent  decay,  keep  the 

teeth  clean ;  wash  them  with  water,  soap,  and  toothbrush, 


THESE  TEETH  WERE 
STRAIGHTENED 


EATING  AND  OUR  FOOD  SUPPLY 


135 


after  breakfast  and  every  night  before  going  to  bed. 
Once  a  day  pull  soft  silk  floss  between  the  separate 
teeth.  This  will  draw  out  food  fragments  which  the 
brush  does  not  reach.  Use  tooth  powder  or  paste  two 
or  three  times  a  week.  This  is  often  enough.  Besides 
keeping  the  teeth  clean,  go  to  a  dentist  twice  a  year. 
He  will  keep  them  in  good  repair.  Nor  is  this  all. 
Remember  what  Health  and  Safety  says  about  "  squirrel 


ONE  HALF  OF  THE  PERMANENT  SET  OF  TEETH 

mouth  " —  how  it  happens  and  how  to  prevent  it.  To 
do  proper  chewing,  the  upper  and  the  lower  teeth 
should  be  opposite  each  other.  A  dentist  can  compel 
crooked  teeth  to  grow  straight,  and  the  matter  should 
be  attended  to  while  the  jaw  is  still  young.  Even  five- 
year-old  children  may  help  themselves  by  doing  some 
downright,  energetic  food-chewing  every  day.  If  cereal 
is  used,  serve  dry  toast  with  it.  Use  soft  cereals  less,  use 
crispy  toast  more.  The  chewing  required  for  the  toast 


136        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

will  give  exercise  to  jaws  and  gums,  will  draw  blood  to 
the  chewing  apparatus,  and  will  thus  give  health  and 
vigor  to  the  teeth  themselves.  Such  chewing  will  do 
more  than  anything  else  to  save  children  both  from 
"  squirrel  mouth "  and  from  adenoids. 

Since  we  know  that  our  whole  supply  of  food  gets 
into  use  through  what  the  body  does  to  it  after  it 
has  been  broken  up  by  the  teeth  and  swallowed,  we 
are  now  ready  to  understand  Dr.  W.  B.  Cannon's  experi- 
ments with  cats  under  the  X  ray,  described  in  the  next 
chapter* 

QUESTIONS 

1.  Give  an  account  of  Professor  Chittenden's  food  experiments  with 
soldiers.  2.  Did  these  men  eat  more  or  less  than  other  men  ?  3.  What 
was  the  result?  4.  What  did  the  tests  prove  about  man's  need  of  meat  ? 
5.  What  persons  should  eat  least  meat?  6.  Mention  two  things  that 
food  does  for  the  body.  7 .  What  are  the  five  food  substances  ? 
8.  Whence  do  plants  get  their  nourishment?  9.  Whence  do  animals  get 
theirs?  10.  What  do  the  carbohydrates  include?  11.  Study  the  food 
table  and  tell  which  foods  are  richest  in  proteids ;  in  carbohydrates ;  in 
fats.  12.  What  is  said  about  dry  and  moist  foods?  13.  What  substance 
surrounds  each  separate  starch  granule  and  must  be  broken  up  by  cook- 
ing? 14.  Which  food  substance  gives  us  energy?  15.  If  we  eat  more 
carbohydrate  than  we  need,  what  does  the  body  do  with  the  surplus  ? 

16.  What  is  animal  proteid  ?  plant  proteid  ?  17.  What  does  the  body 
make  of  proteid  food  ?  18.  If  we  eat  more  proteid  than  we  need,  what 
becomes  of  the  surplus  ?  19.  Where  does  the  fat  in  our  food  come  from  ? 

20.  What  are  the  general  laws  of  proper  eating?  21.  Why  do  we 
feel  hungry?  22.  When  Professor  Chittenden  selected  beans,  cheese, 
or  eggs  for  his  men,  why  did  he  give  them  little  meat?  23.  Why  are 


EATING  AND  OUR  FOOD  SUPPLY  137 

creamed  potatoes  more  nourishing  than  plain  boiled  potatoes  ?  24.  Why 
is  macaroni  and  cheese  so  nourishing  ?  25.  How  much  water  should  we 
drink  ?  Why  ?  26.  What  do  we  mean  by  a  "balanced  menu"  ?  27.  Give 
the  menu  for  a  healthful  breakfast ;  luncheon  ;  dinner.  28.  Why  is  bulk 
of  food  needed  ?  29.  What  gives  bulk  ?  30.  Describe  the  teeth  and  tell 
why  they  should  be  kept  clean.  31.  How  is  this  done  ?  32.  What  is  the 
cause  of  toothache  ?  33.  Why  should  crooked  teeth  be  straightened  ? 


CHAPTER  X 

FROM  FOOD  TO  BLOOD,  OR  THE  PROCESS 
OF  DIGESTION 

Food  Experiments  with  Cats.  These  experiments  were 
carried  on  in  the  laboratory  of  the  Harvard  Medical 
School,  and  the  record  of  the  work  was  published  in 
1898.  Cats  were  chosen  because  they  are  easy  to  get 
hold  of,  ready  to  eat  when  they  are  fed,  ready  to  sleep 
at  almost  any  time,  and  easily  controlled.  Even  among 
cats,  however,  Dr.  Cannon  had  to  choose  carefully,  for 
only  those  who  were  good-natured  were  useful. 

Having  made  his  choice,  he  took  bread,  mixed  into  it 
a  harmless  chemical  called  bismuth,1  fed  it  to  his  cats, 
and  waited  for  results.  The  bismuth  was  put  in  for  only 
one  reason :  its  presence  in  the  food  made  it  possible 
to  get  a  shadow  of  the  image  of  the  stomach  by  means 
of  X  rays.  From  the  shadows  he  hoped  to  discover  ex- 
actly how  the  stomach  moves  during  the  time  that  it  is 
digesting  its  contents.  Dr.  Cannon  was  fortunate  in  the 
cats  he  chose,  fortunate  in  his  helpers,  and  fortunate  in 
what  he  was  able  to  learn  through  the  X  rays ;  for  he 
learned  facts  which  had  never  been  proved  before. 

1  The  exact  chemical  name  is  bismuth  subnitrate. 
138 


FROM  FOOD  TO   BLOOD  139 

Under  the  X  Ray.  After  being  fed,  at  a  quarter  of 
eleven  in  the  morning,  the  cat  was  put  in  place  for  its 
shadow  picture.  At  eleven  o'clock  work  was  well  under 
way  in  the  stomach,  and  once  every  half  hour  after  that, 
until  twelve  minutes  after  six  in  the  afternoon,  the  kindly 
cat  consented  to  have  its  shadow  studied.  Dr.  Cannon 
traced  the  shadows  one  by  one,  so  that  an  exact  record 
was  kept  of  the  size  of  the  stomach  from  the  time  of  the 
hearty  feeding  until  there  was  nothing  left  to  be  digested. 

During  this  time  there  was  an  interesting  course  of 
events.  When  first  seen  the  stomach  looked  like  a  small 
leg  of  ham  with  a  curled-up  tail  to  it,  but  when  six 
o'clock  came  the  leg  shape  had  disappeared  entirely, 
leaving  nothing  but  the  tail  to  show  where  the  food  had 
been.  Moreover,  by  this  time  the  cat  seemed  hungry 
and  called  for  food,  with  which  it  was  promptly  rewarded. 

The  Stomach  during  Digestion.  The.  diminishing  size 
of  the  stomach  was  perhaps  one  of  the  least  important 
lessons  learned  that  day ;  for  while  the  cat  slept,  and 
while  the  X  rays  were  focused  on  its  stomach,  another 
fact  was  noted.  It  appeared  that  food  which  had  newly 
arrived  stayed  quietly  in  the  upper  end  of  the  stomach 
as  if  it  were  in  a  reservoir.  Here  the  saliva  which  had 
been  swallowed  with  the  food  had  a  longer  time  to 
do  its  share  in  the  work  of  digestion.  But  as  fast  as 
supplies  were  needed  farther  on,  this  reservoir  contracted 
itself  and  sent  its  contents  forward,  a  little  at  a  time. 


140        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


4.00 


Q  6.0( 

CONTRACTION  OF 

CAT'S  STOMACH 

(MUCH  REDUCED) 

DURING  DIGESTION 


It  was  also  seen  that  the  firm  walls 
of  the  lower  part  of  the  stomach  began 
to  contract  in  a  series  of  wavelike 
movements.  These  waves  started  near 
the  middle  of  the  stomach  and  moved 
towards  the  smaller  end  of  the  elastic 
bag.  Every  ten  seconds  a  new  wave 
took  its  start  from  about  the  same  spot 
and  traveled  the  same  course  down  to 
the  pylorus  at  the  smaller  end. 

Indeed,  whenever  the  shadows  were 
studied  during  the  day,  these  waves 
were  seen  to  be  following  each  other 
with  unceasing  regularity.  Moreover, 
as  time  passed  and  as  digestion  pro- 
gressed, this  middle  part  of  the  stomach 
grew  gradually  more  and  more  slender, 
like  a  neck,  while  the  larger  end  stayed 
large  for  a  longer  time. 

Through  his  study  of  shadows  Dr. 
Cannon  learned  that  within  about  fif- 
teen minutes  after  food  is  swallowed  a 
slender  jet  of  softened  food  goes  with  a 
spurt  through  an  opening  at  the  lower 
end  of  the  stomach  and  out  into  the 
tube  which  is  the  beginning  of  the 
small  intestine. 


FROM  FOOD  TO  BLOOD  141 

Entrance  and  Exit  of  Food.  For  all  animals,  including 
man,  the  entrance  of  the  stomach  is  controlled  by  what 
is  known  as  the  circular  cardiac  muscle.  This  stays 
closed  except  when  food  must  enter.  The  exit  for  the 
contents  of  the  stomach  is  guarded  by  another  strong 
circular  muscle,  called  the  pylorus,  or  keeper  of  the  gate. 
And  well  does  this  gatekeeper  do  its  work.  Sometimes 
with  every  wave  that  rolls  in  its  direction  it  opens 
wide  enough  to  allow  a  spurt  of  digested  liquid  food, 
called  chyme,  to  go  through,  but  sometimes  it  stays 
persistently  shut  while  wave  after  wave  pushes  in  vain 
in  its  direction. 

Use  of  Bismuth.  To  get  an  explanation  of  this  uneven 
action  of  the  pylorus,  Dr.  Cannon  induced  the  cat  to 
swallow  a  small,  specially  prepared  tablet,  made  up  of 
starch  paste  and  bismuth.  He  then  watched  the  prog- 
ress of  this  pellet  in  the  stomach.  He  saw  it  stay  for 
a  long  time  in  the  cardiac  end ;  saw  it  gradually  make 
its  way  farther  and  farther  down  as  it  was  sent  forward 
by  the  waves  of  contractions;  and  finally  saw  that  for 
forty-two  minutes  after  the  pellet  reached  the  pylorus 
that  watchful  gatekeeper  allowed  nothing  to  pass 
onward. 

Over  and  over  again  the  pellet  and  the  mass  of  soft 
food  in  which  it  floated  came  up  to  the  pylorus  as  if 
to  demand  free  passage  through,  and  over  and  over 
again  the  soft  as  well  as  the  hard  was  positively  rejected 


1 42        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

and  sent  shooting  backwards,  only  to  come  again  and 
again  to  be  rejected. 

This  was  kept  up  until  finally  the  most  fluid  of  the 
food  was  held  back  no  longer.    It  went  onward.    Later 

(Esophagus  - 

Cardiac_ 
Musch~       \> 
_   I          1 
Bladder 


Bile  Duct 


Intestine 


Pancreatic  Duct 


THE  HUMAN  STOMACH 

Food  reaches  the  stomach  from  the  mouth  through  the  oesophagus.  While 
digestion  goes  on,  bile  runs  from  the  liver  directly  into  the  intestine ;  at  other 
times  the  opening  of  the  bile  duct  is  shut,  and  instead  of  entering  the  intestine, 
bile  passes  into  the  gall  bladder,  where  it  is  stored  until  needed.  The  outline  of 
the  pancreas  is  shown  by  a  dotted  line 

the  pylorus  seemed  to  give  up  all  protest.  It  seemed  to 
conclude  that  there  was  no  hope  of  ever  softening  that 
bismuth  and  so  allowed  it  to  go  on  in  company  with 
food  which  was  properly  prepared.  The  pylorus  is  in- 
deed a'  faithful  guardian  of  the  food  supply. 


FROM  FOOD  TO  BLOOD  143 

Undigested  Substances.  From  this  experiment  it  is 
evident  that  any  hard  substance  in  the  stomach  is  not 
only  slow  in  passing  on  through  the  pylorus,  itself,  but 
that  it  delays  the  progress  of  even  such  food  as  has 
already  been  reduced  to  chyme  —  food  which  should  be 
receiving  its  next  course  of  treatment  in  the  food  tube. 
The  main  objection  to  slow  digestion  is  that  after  food 
has  stayed  too  long  in  the  stomach  it  ferments  and  gives 
off  gases  which  stretch  the  walls  of  the  stomach  and 
cause  distress  of  various  kinds. 

The  next  time  you  eat  in  a  hurry  and  are  tempted 
to  swallow  unchewed  lumps  of  food,  think  of  the  bis- 
muth pellet  and  control  yourself  in  time. 

Emotions  that  Hinder  Digestion.  During  the  X-ray 
experiments  there  came  an  unexpected  turn  to  affairs 
one  day.  Thus  far  Dr.  Cannon  had  been  fortunate 
enough  to  have  dealings  with  amiable  cats  only.  They 
had  eaten  when  he  wished,  had  been  quiet  and  well- 
mannered  during  the  experiments,  and  had  slept  when 
required.  In  addition,  their  stomachs  had  gone  steadily 
to  work  when  food  was  put  into  them  and  had  kept 
ploddingly  at  it  until  digestion  was  completed. 

But  a  different  type  of  cat  came  to  Dr.  Cannon's 
hands  one  morning.  This  one  ate  as  promptly  as  the 
others,  and  when  the  X  ray  was  arranged,  the  shadow 
showed  at  first  that  the  usual  regular  wave  action  of 
the  muscular  walls  was  taking  place.  Suddenly,  however, 


144        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

the  animal  lost  his  temper.  He  seemed  to  feel  out- 
raged at  what  was  being  done.  He  refused  to  purr 
as  did  the  other  cats ;  he  insisted  on  being  released. 
Being  in  such  a  state  of  mind,  he  was  useless  and  had 
to  go.  But  before  he  was  dismissed,  the  X  ray  showed 
that  all  the  waves  had  stopped;  so  much  so,  that  the 
stomach  was  as  inactive  as  if  it  were  empty. 

This  led  to  close  observation  of  the  connection  be- 
tween the  feelings  of  a  cat  and  the  behavior  of  its 
stomach  during  digestion.  Then  came  the  surprising 
discovery  that  whenever  a  cat  is  unhappy,  or  disturbed 
in  its  mind  by  anger,  anxiety,  or  distress  of  any  descrip- 
tion, the  muscular  action  of  the  stomach  comes  to  an  end. 

To  prove  this  conclusively  those  who  carried  on  the 
experiments  had  to  tease  a  well-disposed  cat  a  little, 
even  while  it  was  under  the  rays.  Before  the  teasing 
it  purred  gently,  and  the  wave  contractions  swept  on 
with  rhythmic  regularity.  But  when  the  teasing  began 
and  when  the  cat  felt  mental  distress  every  wave  ceased ; 
the  stomach  stopped  its  work  abruptly  and  absolutely. 
But  if  at  this  point  Dr.  Cannon  stroked  the  cat,  it 
was  at  once  happy  and  purred.  And  with  the  purring 
began  again  the  squeezing  and  the  regular  progress  of 
the  waves  along  the  walls  of  the  stomach. 

Happiness  and  Good  Digestion.  Doctors  have  always 
known  that  an  unhappy  man  does  not  digest  his  food 
so  well,  as  the  same  man  when  happy,  but  none  have 


FROM  FOOD  TO  BLOOD 

known  just  why  this  is  so.  It  is  evident,  however,  that 
there  is  some  close  connection  between  happiness  and 
the  power  of  the  stomach  to  keep  up  the  squeezing 
movement  of  its  waves. 

In  view  of  this  discovery 
we  plainly  see  that  if  we 
wish  good  work  from  our 
own  stomachs  we  must  be 
neither  worried  nor  anxious 
nor  angry,  either  during  the 
time  that  we  are  eating  or 
as  long  afterwards  as  food 
is  in  our  stomachs  waiting 
to  be  digested.  For  the  sim- 
ple sake  of  health,  therefore, 
the  calm  and  happy  mind 
is  greatly  to  be  desired. 

When  to  take  Exercise.  For 
health's  sake  never  take  hard 
exercise  of  body  or  mind  just 
before  or  just  after  a  meal. 
Such  exercise  draws  blood 
away  from  the  region  of  the 

Stomach     just     when      special  THE  ROAD  THE  FOOD  TAKES 

supplies  of  it  are  needed  for  digestion.  We  should  have 
a  restful  as  well  as  a  happy  feeling  at  mealtime,  and  only 
by  planning  for  this  condition  shall  we  get  it. 


146        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

The  Digestive  Apparatus.    The  following  definite  state- 
ments are  needed  for  the  closing  of  this  section : 

'i.  The  alimentary  canal  is  the  one  food  avenue 
of  the  body.  It  extends  from  the  mouth  downward 
through  the  center  of  the  body  and  is  of  different 
size  and  shape  in  different  parts  according  to  the 
work  it  has  to  do.  Throughout  its  course  its  walls 
are  controlled  by  muscles  which  differ  with  the  kind 
of  squeezing  and  pulling  which  is  required  of  them. 
In  addition,  the  entire  alimentary  canal  is  lined 
with  mucous  membrane,  delicate,  pink,  and  elastic. 
It  is  always  moist,  so  that  food  may  move  through 
it  easily. 

2.  The  mouth  is  a  cavity  supplied  with  teeth  for 
the  breaking  up  of  food  into  bits,  a  tongue  for  roll- 
ing food  from  side  to  side,  and  saliva  for  the  soften- 
ing of  this  food.    When  ready  to  be  swallowed,  the 
pulplike  mass  of  chewed  moist  food  is  laid  hold  of 
by  muscles  at  the  back  of  the  mouth  and  forced 
through  the  pharynx  into  the  oesophagus. 

3.  The  oesophagus  extends  onward  to  the  stomach. 
Through  it  food  goes  down,  not  as  a  stone  into 
a   well,  but   as  a  package  which   careful   muscles 
pass  along  by  a  squeezing  movement.    On  its  way  it 
slides  safely  over  the  epiglottis, which  has  closed  down 
suddenly  over  the  glottis.  When  the  food  has  passed, 
the  epiglottis  lifts  and  the  glottis  is  open  again. 


FROM  FOOD  TO  BLOOD 


147 


4.  The  stomach   is    that  part  of   the  alimentary 
canal  which  has  been  stretched  out  into  a  good- 
sized  pouch.    Its  entrance  is  guarded  by  the  strong, 
circular  cardiac  muscle ;  its 

exit  by  the  pylorus  muscle, 
equally  strong  and  equally 
circular.  While  food  is  in  it, 
the  stomach  keeps  up  a  con- 
stant kneading  movement, 
which  sweeps  like  slow  waves 
from  the  cardiac  to  the  py- 
loric  end.  At  the  same  time 
gastric  glands  in  the  walls 
of  the  stomach  pour  out 
gastric  juice  from  thousands 
upon  thousands  of  tiny  open- 
ings, thus  softening  still  fur- 
ther the  food  that  came  from 
the  mouth.  When  all  is  as 
liquid  as  pea  soup  the  py- 
loric  muscle  relaxes,  and  the 
prepared  stream  of  chyme 
shoots  its  way  through  into 
the  small  intestine.  After  it 
enters  the  intestine  the  food  substance  is  called  chyle. 

5.  The  small  intestine  is  about  twenty  feet  long, 
yet  it  is  only  a  single  part  of  the  alimentary  canal. 


VlLLI  THAT    FORM   THE 

VELVET  LINING  OF  THE 
FOOD  TUBE 

A  cut  through  the  wall  of  the 

tube,  showing  some  dark  blood 

vessels  and  four  villi 


148        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

The  entire  tube  is  coiled  up  in  compact  fashion  just 
below  the  stomach  and  the  liver,  and  it  expands 
or  contracts  with  the  amount  of  chyle  that  it  holds. 

6.  The  villi.   The  mucous-membrane  lining  of  the 
intestine  is  covered  with  slender  projections  called 
villi,  of  which  much  will  be  said  a  little  later  on. 
They  absorb  the  soluble  food  for  the  use  of  the  body. 
As  food  passes  through  the  small  intestine  it  grows 
constantly  softer  because  several  fluids  are  being 
added  to  it. 

7.  The  large  intestine  and  the  colon  form  the  final 
five  feet  of  the  alimentary  canal.    Here  the  food  con- 
tinues to  be  absorbed  somewhat  and  to  be  passed 
along  until  all  that  is  left  is  sent  from  the  body 
as  waste. 

Peristaltic  Action1  and  the  Villi.  Keeping  these  facts 
about  the  canal  itself  in  mind,  we  are  prepared  to  under- 
stand how  it  is  that  the  food  supply  in  the  tube  gets 
into  the  blood  supply  of  the  body.  In  other  words,  we 
are  ready  to  appreciate  the  wonderful  importance  of 
peristaltic  action  and  the  villi. 

In  the  same  laboratory  of  the  Harvard  Medical 
School,  and  probably  on  the  identical  cats  already  de- 
scribed, a  second  set  of  experiments  was  made,  in  order 


1  This  means  "the  peculiar  wormlike,  wave  motion  of  the  intestines,  produced 
by  the  contraction  of  the  muscular  fibers  of  their  walls,  forcing  their  contents 
onwards."  ' 


FROM  FOOD  TO  BLOOD 


149 


to  determine  what  is  the  history  of  chyme  after  it  has 
gone  through  the  pylorus  into  the  tube  of  the  intestine 
and  has  its  new  name  "chyle." 

The  entire  scientific  world  was  in  doubt  as  to  precisely 
what  happens  in  the  tube  until,  through  Dr.  Cannon's 


THE  FOOD  TUBE  AND  ITS  CONTENTS 

A,  the  tube  as  it  contracts  at  regular  intervals ;  B,  the  contents  of  the  tube  after 
the  first  contraction ;  C,  after  the  second  contraction ;  D,  after  the  third  contrac- 
tion. The  line  through  the  middle  of  the  oval  piece  shows  where  each  was  divided 
by  the  tube  as  it  tightened  just  there.  The  arrows  show  how  the  new  halves 
were  alternately  forced  apart  and  driven  together  by  the  repeated  contraction 

of  the  tube  itself 

continued  experiments,  the  mystery  was  explained  by 
the  discovery  of  a  series  of  surprising  facts. 

Activity  in  the  Food  Tube.    At  first  the  X  rays  showed 
the  shadow  of  the  chyle  as  it  lay  along  in  the  various 


150       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

loops  of  the  folded  tube.  All  was  inactive  and  quiet  for 
a  season.  Then  came  slight  warnings  —  a  quiver  at  first, 
a  mere  agitation.  Then  without  further  delay,  activity 
began  in  earnest.  The  stretched-out  length  of  chyle 
within  an  entire  loop  was  suddenly  divided  into  sepa- 
rate bits  of  equal  size.  The  tube,  indeed,  without  ap- 
parent cause,  had  tightened  itself  at  regular  intervals; 
like  a  flash  it  had  divided  its  contents  into  a  series 
of  oval  masses  of  equal  size.  After  this  it  halted  for 
a  moment.  But  within  two  seconds  there  was  another 
contraction,  and  each  bit  was  now  divided  through  the 
middle;  their  halves  were  compelled  to  unite  with 
neighbor  halves  on  either  side,  and  a  series  of  new 
whole  ones  appeared. 

Thus,  back  and  forth,  every  two  seconds,  the  rapid 
peristaltic  action  was  continued. 

The  small  masses  of  chyle  were  alternately  so  quickly 
divided  and  so  quickly  forced  together  again  that  Dr. 
Cannon  speaks  of  them  as  rushing  together  "with  the 
rapidity  of  flying  shuttles,  the  little  particles  flitting  to- 
wards each  other  and  the  larger  segments  shifting  to 
and  fro,  commonly  for  more  than  half  an  hour  without 
cessation." 

In  the  meantime  the  food  within  the  tube  was  advanced 
but  slowly  on  its  way.  It  seemed  to  stay  in  place  for  no 
other  purpose  than  to  be  acted  upon  by  the  squeezing 
and  relaxing  of  the  tube.  Whether  the  chyle  was  thin 


FROM  FOOD  TO  BLOOD 


A 


B 


or  thick,  whether  the  contraction  was  slow  or  swift,  the 

squeezing  was  kept  up  so  unweariedly  that  each  particle 

of  chyle  was  affected  by  it.    All  that  lay  within  the  folds 

and  turns  of  the  small  intes- 

tine was  brought  into  contact 

with    the    sides    of   the   tube 

thousands   of   times   while   it 

was  gradually  being  absorbed. 

That  which  could  not  be  used 

went  on  into  the  large  intes- 

tine, whence  it  would  finally 

leave  the  body. 

Relation  of  Chyle  to  the 
Villi.  To  an  ignorant  person 
this  endless  activity  might 
seem  to  be  a  waste  of  energy 
and  a  needless  hindrance  to 
the  chyle  as  it  is  worked  along. 
In  point  of  fact,  however,  rapid 


Ct    capillaries    to 

eac^  J111"8  'with  blood; 

Z>,  lymphatic 


A   VlLLUS   CUT  DOWN   THROUGH 

THE  MIDDLE 
^  a  cel1  which  manufactures  mu- 

cus;    B,   the   outside   layer,  which 
movement     Of     Chyle     through      absorbs    chyle; 

the  food  tube  would  be  a  dis- 

tinct  disadvantage  ;    for  from 

the  time  food  is  swallowed  until  its  journey  is  ended,  the 

one  necessity  is  that  it  should  be  thoroughly  prepared 

to  be  used  by  the  regiments  of  threadlike  villi  which 

line  the  small  intestine.    Chyle,  indeed,  is  improved  by 

every  juice  that  is  mixed  with  it  and  by  every  squeeze 


152        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

which  it  receives  before  it  is  absorbed  by  the  villi.  So 
true  is  this,  that  food  which  does  not  get  the  treatment 
it  needs  will  be  rejected  by  each  villus  which  it  meets 
as  it  travels  downward  and  will  end  by  forming  part  of 
the  final  waste  of  the  body. 

Food  Waste.  With  all  that  we  eat  there  is,  of  course, 
much  that  can  never  be  turned  into  chyle  and  blood. 
We  know,  however,  that  this  is  useful  as  bulk.  But 
nothing  hinders  digestion  much  more,  or  breaks  down 
general  health  much  faster,  than  the  results  which  come 
from  retaining  waste  in  the  body  after  it  should  be  sent 
off.  Waste  decays  in  the  body  just  as  meat  and  vege- 
tables decay  in  the  pantry  on  a  warm  day.  Both  in  the 
pantry  and  in  the  food  tube,  decay  comes  from  the  action 
of  microbes,  and  from  both  places  decaying  food  should 
be  cleared  away  promptly.  The  habit  of  getting  rid  of 
waste  at  a  definite  hour  each  day,  whether  in  the  morn- 
ing or  in  the  afternoon,  is  of  priceless  value,  for  that 
which  the  villi  reject  is  worse  than  useless  to  the  body. 
More  is  said  of  this  later. 

QUESTIONS 

1.  Describe  Dr.  Cannon's  experiments  with  cats.  2.  Where  does 
the  wavelike  motion  of  the  stomach  begin?  3.  Describe  the  changing 
shape  of  the  stomach  during  digestion.  4.  How  soon  after  eating  does 
food  begin  to  leave  the  stomach?  5.  Name  the  muscle  that  guards  the 
outlet.  6.  How  does  the  pylorus  act  when  an  undigested  substance 
reaches  if?  7.  What  did  Dr.  Cannon's  experiment  prove?  8.  Why  is 


FROM  FOOD  TO  BLOOD  153 

it  a  disadvantage   to   have  food  detained  too  long  in  the  stomach  ? 

9.  What  emotions  have  the  power  to  stop  all  action  of  the  stomach? 

10.  What  condition  of  mind  helps  at  the  dining  table? 

1 1 .  Describe  the  alimentary  canal ;  the  mouth ;  the  oesophagus  ;  the 
stomach.  12.  Where  is  the  cardiac  muscle  ?  the  pylorus  muscle  ? 
13.  Describe  the  kneading  movement  of  the  stomach.  14.  What  is 
manufactured  by  gastric  glands?  15.  How  soft  does  food  get  in  the 
stomach?  16.  What  is  it  then  called?  17.  Describe  the  way  chyme 
leaves  the  stomach.  18.  What  is  the  length  of  the  small  intestine? 
19.  Where  is  it  located?  20.  What  is  chyle?  21.  What  and  where 
are  the  villi? 

22.  What  was  the  object  of  the  second  set  of  experiments  on  cats  ? 

23.  Describe  the  action  of  the  small  intestine  as  shown  by  the  X  ray. 

24.  How  did  chyle  move  through  the  tube?    25.  Is  a  rapid  or  slow 
movement  of  chyle  desirable?     26.   What  is  the  work   of  the  villi? 
27.  Why  is  chyle  squeezed  up  against  them?    28.  What  becomes  of 
food  that  is  not  absorbed  by  the  villi  ?     29.  From  the  time  food  is 
cooked  and  eaten  until  its  journey  is  ended,  what  is  all  the  preparation 
for  ?    30.  What  is  each  villus  like  ?    31.  What  is  the  great  object  of  peri- 
staltic action  ?    32.   What  happens  if  food  is  not  thoroughly  prepared 
for  the  villi?   33.  Where  does  food  meet  its  final  test?   34.  What  hap- 
pens to  food  if  it  is  kept  too  long  either  in  the  pantry  or  in  the 
food  tube? 


CHAPTER  XI 

CHEMICAL  ACTION  AND  DIGESTIVE  FLUIDS 

The  Chemical  Fluids  of  Digestion.  No  chemist  in  any 
laboratory  is  able  to  manufacture  chemicals  quite  so 
marvelous  as  those  the  body  manufactures  to  digest 
our  foods.  These  fluids  do  two  things  to  the  food  we 
swallow : 

1.  They  soften  it  thoroughly  and  dilute  it. 

2.  They  so  change  it  that  even  substances  which 
will   not  dissolve  in  water  —  beans,  potato,  bread, 
and  most  other  foods  —  are  so  thoroughly  dissolved 
by  digestive  fluids  that  the  villi  can  absorb  them. 

This  chemical  process  of  dissolving  food  and  getting 
it  ready  for  the  villi  is  called  digestion.  There  are  five 
digestive  fluids.  Each  is  manufactured  in  the  body  and 
sent  into  the  alimentary  canal,  and  each  does  its  own 
special  kind  of  chemical  work.  Follow  them  in  order, 
from  the  mouth  downward. 

I.  Saliva,  from  glands  in  the  mouth.  This  not 
only  softens  food  but  changes  starch  into  sugar. 
Try  the  following  experiment:  Take  a  tablespoon- 
ful  of  cornstarch  paste.  Add  a  teaspoonful  of  saliva, 
mixing  it  thoroughly  with  the  paste.  Keep  it  at 

154 


CHEMICAL  ACTION  AND  DIGESTIVE  FLUIDS      155 

blood  heat  for  a  few  minutes.  It  will  not  only  grow 
thin  and  watery,  but  it  will  soon  have  a  sweetish 
taste.  The  saliva  has  turned  the  starch  into  a 
kind  of  sugar.  This  is  easily  used  by  the  villi. 

2.  Gastric  juice,  from  gastric  glands  in  the  walls 
of  the  stomach.    In  this 

juice  there  are  three 
important  chemicals  — 
pepsin,  rennin,  and  hy- 
drochloric acid.  Rennin 
turns  milk  into  curd 
as  soon  as  it  reaches  the 
stomach.  This  is  most 
important,  for  otherwise 
the  milk  would  go  on 
through  the  pylorus 
without  waiting  to  be  di- 
gested. After  it  is  turned  <*,  artery ;  V,  vein ;  N,  nerve  ;  71,  the 

tongue ;   Z),  the  tube  through  which 
tO    CUrd    by    the    rennin,       saliva,   manufactured   by   the   gland, 

the  pepsin  of  the  gas-          is  emptied  into  the  mouth 
trie  juice  is  able  to  take  hold  of  it  and  digest  it. 
Curd  is  a  proteid,  and  pepsin  digests  proteids  if 
hydrochloric  acid   is  present.    Gastric  juice  is  the 
most  important  proteid  digester  of  the  body. 

3.  The  remaining  three  digestive  fluids  are  all 
found  within  the  small  intestine.   Bile,  which  comes 
from  the  liver  through  the   gall  duct,  digests  fat, 


A  SALIVARY  GLAND 


156        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

which  was  simply  melted  in  the  stomach.  Pancreatic 
fluid,  which  comes  from  the  pancreas,  is  a  marvel  of 
power.    It  digests  all  three  substances  —  carbohy- 
drate, proteid,  and  fat.   Intestinal  juice,  coming  from 
the  inside  lining  of  the  whole  length  of  the  tube, 
helps  do  the  general  digesting.    It  gives  final  touches 
to  all  food  sent  down  for  the  use  of  the  villi. 
Number  and  Structure  of  the  Villi.    It  would  seem,  then, 
that  from  first  to  last  each  mouthful  of  food  which  we 
swallow  is  being  put  into  shape  for  the  villi,  and  that 
they  use  it  or  not  without  the  slightest  reference  to  our 
wishes    in    the   matter.     This   indeed  is   true,  and  the 
number  of  these  independent  workers  is  counted  by  the 
hundred  thousand  and  the  million.    Each  separate  one  is 
a  tiny  finger-shaped  structure,  ready  to  absorb  such  chyle 
as  shall  meet  its  demand ;  each  stands  beside  its  neigh- 
bor, helping  to  make  the  soft  velvety  lining  of  the  twenty 
feet  of  tubing;  each  does  its  independent  work,  yet  all 
are  united  in  drawing  nourishment  from  the  chyle  and 
in  sending  it  on  to  the  body  through  the  blood. 

Just  here  certain  facts  should  be  reviewed  and  con- 
densed : 

i.  It  is  through  the  lining  of  the  small  intestine 
that  practically  all  substances  must  pass  —  whether 
proteid  or  carbohydrate,  fat  or  mineral  matter  — 
which  are  to  enter  the  blood  from  the  food  we 
swallow. 


CHEMICAL  ACTION  AND  DIGESTIVE  FLUIDS      157 

2.  The  villi  are,  in  point  of  fact,  the  lining  itself, 
drawn  up  into  slender  tubes  for  the  sake  of  increas- 
ing the  surface  against  which  the  chyle  must  be 
pressed.   They  are  sometimes  called  the  roots  of  the 
body,  for  they  suck  up  nourishment 

from  chyle  just  as  tree  roots  draw 
liquid  from  the  earth. 

3.  Food  passes  through  the  villi 
much  as  lymph  and  plasma  pass 
back  and  forth  through  the  sides  of 
the  tubes  that  carry  blood.    This 
food  must  therefore  be  liquid,  for 
the  villi   cannot  absorb  any  solid 
substance. 

4.  The  great  object  of  peristal- 
tic action  is  to  wash  the  chyle  up 
against  the  villi,  so  that  they  may 
be    constantly   bathed   with    fresh 
supplies  of  it. 

5.  The  mouth  with  its  teeth  and 
its  saliva  softens  food  and  prepares 
it  for  swallowing ;  the  stomach  with 

its  gastric  juice  softens  it  still  further  and  prepares 
it  for  the  pylorus;  the  food  tube,  with  its  contri- 
butions from  the  liver  and  the  pancreas,  and  the 
juices  from  its  own  lining,  gives  to  what  we  eat  its 
final  preparation  for  the  villi. 


BRANCHES  OF  A  GAS- 
TRIC GLAND  HIGHLY 

MAGNIFIED 

Gastric  juice  is  here 

manufactured  for  the 

use  of  the  stomach 


158        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

6.  When  the  chyle  which  is  squeezed  against  the 
villi  is  such  as  they  can  use,  they  absorb  it  and 
send  it  on  through  other  tubes  into  the  current  of 
the  blood.  When,  however,  this  chyle  is  not  liquid 
enough,  or  not  changed  enough  in  other  ways, 
they  refuse  it  as  firmly  as  if  they  knew  it  would 
be  harmful. 

Mistakes  in  Eating.  For  each  of  us  almost  any  well- 
cooked  food  can  be  turned  into  chyle  which  will  pass 
through  the  villi;  yet  many  a  thin  man,  and  many  a  half- 
nourished  woman,  shows  by  every  sign  of  face  and  figure 
that  the  villi  are  not  getting  what  they  can  accept. 

In  almost  every  such  case  the  explanation  lies  in  some 
mistake  which  the  person  is  making.  Perhaps  he  eats  so 
fast  and  chews  so  little  that  the  saliva  does  not  have  a 
chance  to  do  its  share  of  work.  Perhaps  he  is  so  busy 
just  before  and  just  after  eating,  that  blood  is  drawn 
away  from  the  stomach,  leaving  it  less  vigorous  than  it 
should  be.  Perhaps  he  worries  so  much,  is  so  anxious 
and  troubled  about  many  things,  that  gastric  juice  fails 
to  form,  and  thus  its  part  of  the  work  is  not  done.  Or 
it  may  be  that  the  unfortunate  person  has  overeaten 
until  his  whole  digestive  system  has  rebelled.  Whatever 
the  cause,  we  know  that  we  are  nourished  or  starved  ac- 
cording as  we  have  been  successful  or  not  in  preparing 
the  chyle  for  its  last  examination.  If  teeth  and  tongue, 
saliva,  stomach,  gastric  juice,  bile,  and  pancreatic  juice 


CHEMICAL  ACTION  AND  DIGESTIVE  FLUIDS      159 

have  done  their  work  well,  the  final  test  will  be  success- 
fully met  —  the  villi  will  accept  the  food,  and  we  shall  be 
nourished.  If  the  test  is  not  met,  we  shall  suffer  from 
lack  of  nourishment. 

At  this  point  there  arises  an  important  question. 
Does  anything  we  do  ever  help  or  hinder  the  flow 
of  our  digestive  juices? 

Appetite  and  Gland  Activity.  In  studying  this  subject 
Professor  Pavlov,  a  Russian  investigator,  fastened  a  small 
tube  so  ingeniously  to  the  mouth  of  a  dog  that  the 
saliva  ran  into  it  as  fast  as  it  was  formed.  He  then 
made  tests  and  described  them,  one  after  the  other. 

I  now  offer  this  dog  a  piece  of  flesh  and,  as  you  see,  the  tube  fills  up 
at  once  with  saliva.  I  stop  tempting  the  dog,  hang  on  a  new  test  tube, 
.and  give  it  a  few  pieces  of  flesh  to  eat ;  once  more  a  strong  secretion 
of  saliva  results.  A  new  tube  is  now  attached  to  the  funnel,  the  dog's 
mouth  is  opened,  and  a  pinch  of  fine  sand  is  thrown  in ;  again  there  is 
a  flow  of  saliva.  One  may  employ  a  number  of  substances  in  this  way, 
when  a  similar  effect  is  always  produced. 

Flow  of  Saliva.  Many  different  students  have  estab- 
lished the  fact  that  the  mouths  of  dogs,  and  of  men  too, 
are  supplied  with  three  sets  of  salivary  glands,  and  that 
for  dogs  and  men  alike  one  or  the  other  of  the  two 
following  causes  is  enough  to  make  saliva  flow: 

1.  A  great  desire  for  some  special  kind  of  food. 

2.  The  chewing  of  the  food. 

Prove  these  statements  for  yourself.  Think  of  the 
most  delicious  thing  you  know  anything  about,  and 


160        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

notice  the  effect  on  your  mouth.  Then  again,  when 
mealtime  comes,  take  a  dry  crust  and  see  what  you 
can  do  with  it  by  the  mere  act  of  chewing.  Use  your 
jaws  vigorously,  and  before  long  you  will  find  that  you 
have  turned  that  dry  bread  into  something  as  easy  to 
swallow  as  a  mouthful  of  mush. 

Saliva  and  Carbohydrate.  A  wise  man  with  a  weak 
digestion  often  chooses  toast,  crackers,  and  crusts  rather 
than  the  most  delicate  custards.  He  makes  this  choice 
because  he  knows  that  dry  food  requires  more  chewing 
than  soft  food,  and  that  for  this  reason  it  will  receive 
more  from  his  salivary  glands.  He  realizes  that  the 
more  saliva  we  mix  with  the  carbohydrate  which  we  eat 
in  bread,  potatoes,  and  other  foods,  the  better  prepared 
will  that  carbohydrate  be  for  its  next  course  of  treat- 
ment. He  knows  that  even  after  food  is  swallowed,  the 
saliva  will  continue  to  act  upon  it  in  the  stomach  for 
a  season. 

We  chew  food  thoroughly  for  two  reasons:  first,  to 
soften  it ;  second,  to  mix  it  with  saliva,  which  will  change 
some  of  it  and  prepare  it  for  its  next  course  of  treatment. 

Milk  Digestion.  Carbohydrate  does  not  stand  alone  in 
its  need  of  help  from  the  mouth.  A  baby  is  allowed  to 
draw  no  more  than  the  finest  stream  of  milk  through 
the  mouthpiece  of  his  bottle,  because  when  milk  reaches 
the  stomach  it  is  curdled  at  once,  and  it  is  much  better 
to  have-  it  curdle  in  small  flakes,  that  can  be  more  easily 


CHEMICAL  ACTION  AND  DIGESTIVE  FLUIDS      161 

digested,  than  in  one  large  lump  which  will  be  slow  in 
digesting.  Young  babies  who  are  allowed  to  drink  milk 
rapidly  are  not  likely  to  gain  so  much  nourishment 
from  it  as  they  would  if  it  reached  the  stomach  a 
little  at  a  time.  The  same  is  so  true  for  older  people 
too  that  we  should  all  take  our  milk  in  sips  and  not  in 
a  pouring  stream  which  will  curdle  in  a  mass  as  soon 
as  it  reaches  the  stomach.  Here  the  colorless  acid  fluid, 
gastric  juice,  renders  priceless  service  by  digesting  it. 

Proteid  Digestion.  A  dog  swallows  an  unchewed  piece 
of  raw  meat,  and  his  stomach  digests  it  —  not  by  tearing 
it  to  pieces,  but  in  a  real  way  by  dissolving  it  through 
the  aid  of  gastric  juice,  his  gastric  juice  being  much 
stronger  than  ours.  Even  the  human  stomach  digests 
unchewed  raw  meat,  but  cooked  meat  needs  more  chew- 
ing. Still  it  is  gastric  juice  that  digests  both  cooked 
and  uncooked  meats.  The  small  gastric  glands  which 
manufacture  this  liquid  are  packed  snugly  side  by  side 
within  the  lining  of  the  stomach.  Each  is  supplied  with 
its  separate  tube,  ending  in  its  own  special  outlet.  And 
the  fluid  which  these  hosts  of  glands  secrete  and  empty 
into  the  stomach  flows  faster  or  slower  according  to 
circumstances.  Dr.  Pavlov  discovered  this  through  his 
dogs.  He  found  that  he  could  often  control  the  flow 
by  his  experiments.  Here  is  one  which  he  describes: 

The  stomach  has  been  washed  out  half  an  hour  ago,  and  since  then 
not  a  drop  of  gastric  juice  has  escaped.  We  begin  to  get  ready  a  meal 


1  62        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

of  flesh  and  sausage  before  the  animal,  as  if  we  meant  to  feed  it.  We 
take  the  pieces  of  flesh  from  one  place,  chop  them  up,  and  lay  them  in 
another,  passing  them  in  front  of  the  dog's  nose.  The  animal,  as  you 
see,  manifests  the  liveliest  interest  in  our  proceedings,  stretches  and 
distends  itself,  endeavors  to  get  out  of  its  cage  and  come  to  the  food, 
chatters  its  teeth  together,  swallows  saliva,  and  so  on.  Precisely  five 
minutes  after  we  begin  to  tease  the  animal  in  this  way,  the  first  drops 

of  gastric  juice  appear.  The  secretion  grows 
stronger  and  stronger  till  it  flows  in  a 
considerable  stream.  The  meaning  of  this 
experiment  is  so  clear  as  to  require  no  ex- 
planation ;  the  passionate  longing  for  food, 
and  this  alone,  has  called  forth  a  most 
intense  activity  of  the  gastric  glands. 

In   carrying   on    these    experi- 
ments Professor  Pavlov  made  it 

A  FRAGMENT  OF  THE  LINING 

OF  THE  STOMACH  MAGNIFIED      plain  that  dogS  should  not  Simply 
TWENTY  DIAMETERS  be     tempted    but    should     be    fed 

with  whatever  temted  them- 


gastric   juice    flows    into    the  Effect   Of   Appetite   OH    Digestion. 

Several  other  facts  were  brought 

out  by  the  same  tests.    Each  was  valuable  from  a  scien- 
tific point  of  view,  and  I  give  them  in  close  succession  : 

1.  The  more  eagerly.  a  dog  desires  food  the  more 
gastric  juice  will  flow. 

2.  Gastric    juice    flows    fastest    and    longest    in 
connection   with   food   that   is   enjoyed    the   most; 
for  some  dogs  this  is  raw  meat,  for  others  cooked 
meat.    Dogs  have  preferences  as  well  as  men. 


CHEMICAL  ACTION  AND  DIGESTIVE  FLUIDS      163 

3.  The  mere  fact  that  something  is  in  the  dog's 
stomach  does  not  make  the  juice  flow. 

4.  The  more  the  juice  flows  the  better  will  the 
food  digest. 

From  these  important  facts,  learned  through  the  study 
of  digestion  in  dogs,  men  now  know  why  it  is  that  a 
good  appetite  helps  digestion.  Indeed,  the  call  of  the 
body  for  food  —  if  it  is  not  too  long  continued  —  is  one 
of  the  greatest  blessings  of  life,  and  he  who  eats  only 
when  he  has  earned  an  appetite  for  food  is  sure  to 
gain  the  most  nourishment  from  that  which  he  puts 
into  his  stomach,  because  while  it  is  there  it  will  receive 
the  richest  supply  of  gastric  juice. 

But  aside  from  digestion  itself,  there  is  the  great 
matter  of  preparing  food  for  the  glands  even  before 
we  eat  it. 

Why  we  Cook  our  Food.  Turn  back  to  the  food  table 
and  decide  why  we  do  so  much  cooking.  There  are 
three  reasons: 

i.  For  the  sake  of  health  ;  to  make  the  food  more 
digestible.  Cooking  is  really  a  first  step  in  the 
process  of  digestion,  and  there  is  far  more  danger 
that  food  will  be  undercooked  than  overcooked. 
Take  oatmeal  and  other  breakfast  foods  for  exam- 
ple. They  contain  a  good  deal  of  starchy  carbo- 
hydrates (study  the  table  again),  and  those  who  do 
not  understand  about  cellulose  may  consider  them 


164       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

ready  to  be  eaten  long  before  the  tiny  cellulose  cell 
has  been  broken  up  by  boiling.  An  hour  of  boil- 
ing for  oatmeal,  and  half  an  hour  for  more  finely 
powdered  grains,  is  none  too  long.  Undigested  food 
ferments  easily  and  produces  gas.  This  is  harmful 
to  health. 

2.   To  destroy  microbes  which  may  be  in  the  food 
or   on   it     Recall    the   facts   about   this   given   in 

Health  and  Safety.  Re- 
member that  cooking  kills 
microbes,  and  that  a  dead 
microbe  is  as  harmless  as 
a  dead  lion. 

3.  To  improve  the  taste 
of  food.  Glance  along  the 
list  of  foods  and  think  of 
the  difference  it  makes  in 
the  taste  of  these  vegeta- 

Hes,  grains,  and  meats,  whether  they  are  cooked  or 
not.  Also  remember  the  fact  that  digestive  juices 
flow  fastest  when  we  enjoy  our  food.  Cooking  helps 
us  to  enjoy  it. 

Harmful  Substances.  It  is  perfectly  possible,  however, 
to  enjoy  what  does  harm.  For  years  people  believed  that 
chocolate  and  cocoa  were  good  drinks  for  children,  and 
that  tea  and  coffee  were  bad  for  them.  Nowadays,  how- 
ever, food  experts  condemn  all  these  drinks.  They  say 


A  BIT  OF  POTATO,  SHOWING 
STARCH  GRANULES 


CHEMICAL  ACTION  AND  DIGESTIVE  FLUIDS      165 

that  the  same  poison  is  in  each  drink,  and  that  it  stimu- 
lates brain,  heart,  and  nervous  system.  In  coffee  this 
stimulant  is  called  caffeine ;  in  cocoa  and  chocolate,  theo- 
bromine ;  in  tea,  theine.  There  is  more  of  the  harmful 
substance  in  tea  and  coffee  than  in  cocoa,  so  that  cocoa 
and  chocolate  are  less  harmful  than  tea  and  coffee,  but 
in  every  case  the  stimulant  is  as  bad  for  tired  heart, 
brain,  and  nerves  as  a  whip  is  for  a  tired  horse.  Then, 
too,  in  tea  and  coffee  there  is 
a  substance  called  tannin.  The 
more  the  drink  is  boiled  the 
more  tannin  it  holds.  "  Puckery  " 
tea  contains  much  tannin  and  is 
most  objectionable.  Tannin  is 
used  for  the  tanning  of  hides. 
When  we  swallow  it  in  tea  and 

FROM  THE  SEED  OF  THE  BEAN 
Coffee  We   put   into    the    Stomach       The  larger  granules  are  starch, 

a  substance  that  can  disturb  the       the  smaller  ones  are  Proteid 
best   working   of   the  digestive    apparatus.    If   tea  and 
coffee  are  made  by  simply  pouring  boiling  water  over 
them,  they  contain  little  tannin,  but  the  caffeine  and 
theine  remain. 

Candy  and  sweetmeats  in  quantity  do  harm  too,  be- 
cause our  digestive  apparatus  has  no  device  for  easily 
getting  rid  of  large  amounts  of  cane  sugar.  None  of  it 
is  digested  in  the  small  intestine.  If,  however,  a  person 
is  healthy,  and  if  candy  is  eaten  moderately  at  mealtime, 


1 66        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

it  will  do  no  real  harm.  But  if  it  is  eaten  between  meals, 
when  the  stomach  is  empty,  it  becomes  an  irritating  acid 
in  the  stomach.  The  following  is  quoted : 

A  German  scientist  observed  in  experiments  upon  a  dog  that  a  solu- 
tion containing  six  per  cent  of  cane  sugar  caused  irritation,  with  red- 
dening of  the  mucous  membrane.  A  ten-per-cent  solution  produced  a 
dark-red  color,  with  great  irritation,  and  caused  the  animal  great  pain. 

From  the  work  of  the  stomach  and  of  the  large  num- 
ber of  small  digestive  glands,  turn  now  to  the  daily  and 
hourly  occupation  of  the  largest  glands  of  the  body,  our 
vigilant  and  untiring  protectors,  the  liver  and  the  kidneys. 

QUESTIONS 

1.  How  many  digestive  juices  are  there?  2.  What  two  things  do 
digestive  juices  do  for  food  ?  3.  Give  the  names  of  the  chemicals  which 
are  in  gastric  juice.  4.  What  does  rennin  do  to  milk  in  the  stomach  ? 
5.  Why  is  this  action  important?  6.  What  does  pepsin  do  to  curd? 
7.  Is  curd  a  proteid  or  a  carbohydrate  ?  8.  What  is  the  most  important 
proteid  digester  of  the  body  ?  9.  What  three  digestive  juices  are  found 
in  the  small  intestine?  10.  Where  does  bile  come  from?  11.  What 
does  it  digest?  12.  Where  does  pancreatic  fluid  come  from?  13.  What 
three  things  does  it  digest  ?  14.  What  does  intestinal  juice  do  ?  15.  How 
do  the  villi  help  the  food  to  pass  through  the  lining  of  the  small  intestine  ? 
16.  Why  is  the  lining  itself  drawn  up  into  these  slender  tubes  called 
villi?  17.  How  numerous  are  they?  18.  Why  are  the  villi  called  the 
roots  of  the  body?  19.  Why  does  food  need  to  be  a  thin  liquid? 
20.  What  is  the  great  object  of  peristaltic  action?  21.  Describe  the 
history  of  a  mouthful  of  food,  from  the  time  we  begin  to  chew  it  until 
the  villi  absorb  it.  22.  When  a  person  is  half  nourished,  what  may  be 
the  trouble  ? 


CHEMICAL  ACTION  AND  DIGESTIVE  FLUIDS      167 

23.  Tell  what  you  can  about  the  effect  of  tempting  a  dog  with  meat. 
24.  How  many  sets  of  salivary  glands  are  there?  25.  What  two  things 
make  saliva  flow?  26.  Why  does  a  sensible  man  with  a  weak  stomach 
eat  dry  toast  rather  than  delicate  custard?  27.  How  does  saliva  affect 
starch  ?  28.  After  food  is  swallowed,  where  does  saliva  continue  its  work  ? 
29.  Give  two  reasons  why  we  should  chew  food  thoroughly.  30.  Why 
should  babies,  and  older  persons  also,  take  their  milk  in  sips  and  not 
in  a  pouring  stream?  31.  What  can  gastric  juice  do  to  raw  meat? 
32.  Which  needs  more  chewing,  raw  or  cooked  meat  ?  33.  Describe  the 
gastric  glands.  34.  Describe  the  tests  with  dogs  which  proved  certain 
points  about  the  flow  of  gastric  juice.  35.  What  should  always  be 
done  after  tempting  a  dog  with  food  ?  36.  Under  what  circumstances 
does  gastric  juice  flow  fastest  and  longest?  37.  What  can  you  say 
about  the  advantages  of  hunger  and  a  good  appetite?  38.  Give  the 
first  reason  why  we  cook  our  food.  39.  How  long  should  we  boil 
oatmeal  and  other  cereals  ?  40.  Give  three  reasons  why  we  cook  our 
food.  41.  Why  is  it  an  advantage  to  enjoy  the  taste  of  our  food? 
42.  Why  are  tea,  coffee,  cocoa,  and  chocolate  objectionable?  43.  Why 
is  much  candy  harmful? 


CHAPTER  XII 

LARGE  GLANDS:  THEIR  USE  AND  ABUSE 

The  Liver  —  what  it  Is  and  what  it  Does.  If  you  are 
thin  enough  to  do  it,  you  might  slip  your  fingers  up 
under  the  edge  of  your  lowest  ribs  on  the  right  side. 
There  you  will  feel  the  outline  of  the  largest  gland  in 
your  body.  The  liver  weighs  between  three  and  four 
pounds,  and  it  is  to  this  organ  that  the  villi  send  much 
of  that  which  they  draw  up  from  the  chyle.1  The  follow- 
ing are  the  occupations  of  the  liver: 

1.  It  changes  part  of  the  liquid  food  which  it 
receives  from  the  villi  into  a  sugar  substance  called 
glycogen.    It  stores  up  this  glycogen  in  its  own  liver 
tissues  and  keeps  it  there  until  it  is  needed  for  the 
work  of  the  body.    The  liver  is  thus  a  glycogen 
storehouse,  a  bank  of  deposit. 

2.  It  takes  certain  wastes  from  the  blood,  makes 
them  over,  and  forwards  them  to  the  kidneys  in 
the  blood   stream,  to   be   sent  from   the  body  by 
the  kidneys. 

1  Part  of  the  food  supply  which  the  villi  gather  from  the  small  intestine  — 
especially  the  part  that  holds  digested  fats  —  does  not  go  direct  to  the  liver. 
Instead,  it  'travels  upward  first  and  reaches  the  heart  by  the  way  of  the  neck. 

1 68 


LARGE  GLANDS:    THEIR  USE  AND  ABUSE        169 

3.  It  manufactures  bile  as  needed.  This  is  sent 
through  the  gall  bladder  and  the  bile  duct  into  the 
small  intestine.  There  it  helps  digestion  and  after- 
wards escapes  with  the  other  wastes  of  the  ali- 
mentary canal.  Into  the  bile  go  certain  captured 


As  THE  NORMAL  LIVER  LOOKS 
(After  Horsley) 

poisons.  For  example,  if  peas  or  pickles  colored 
with  copper  are  eaten,  the  liver  seizes  the  metal, 
sends  as  much  as  possible  into  the  bile,  and  stores 
up  the  rest  within  its  own  cells.  It  does  this  to  keep 
the  poison  from  getting  into  the  blood  stream  and 
going  to  the  rest  of  the  body.  It  is  only  when  there 


1 70       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

is  too  much  poison  for  the  liver  to  manage  that  it 
escapes  into  the  general  blood  stream  and  becomes 
a  menace  to  different  organs  of  the  body.  So  also 
with  other  poisons.  In  a  very  real  way  the  liver  is 
our  daily  protector  from  death  by  poisoning. 

Clearly  enough,  no  man  who  knows  the  facts  and  who 
wishes  to  make  sure  of  his  health  will  care  to  ignore  the 
welfare  of  his  liver  or  to  act  as  if  he  were  ignorant  of 
the  laws  which  control  it.  Nevertheless,  many  of  the  dis- 
coveries about  these  laws  are  so  recent  that  even  some 
well-informed  people  have  failed  to  hear  about  them. 

This  is  true  of  my  neighbor  who  complained  about  his 
liver  the  other  day.  He  said  the  doctor  advised  him  to 
eat  less,  to  exercise  more,  and  to  give  up  his  beer  until 
he  was  in  good  shape  again.  But  against  this  he  pro- 
tested. He  said,  "  Can't  I  judge  what  is  good  for  me  by 
my  own  feelings?"  The  doctor  said  he  could  not,  and 
the  doctor  was  right.  Follow  the  argument  closely. 

Effects  of  Alcohol  on  the  Liver.  Those  of  us  who  have 
ever  seen  a  piece  of  raw  liver  know  how  extraordinarily 
bloody  it  is.  We  also  know  that  every  piece  of  liver  is 
always  deluged  with  its  own  blood.  This  is  inevitable, 
because  the  liver  is  provided  with  an  enormous  number  of 
small  blood  vessels,  each  one  of  which  is  in  active  service. 

When,  therefore,  the  doctor  gave  my  neighbor  that 
advice  about  beer,  he  was  advising  according  to  his  knowl- 
edge of  the  effect  of  alcohol  on  blood  vessels  in  general 


LARGE  GLANDS:   THEIR  USE  AND  ABUSE        171 

He  knew  that  wherever  there  is  an  unusual  supply  of 
capillaries  and  blood-carrying  tubes  of  all  sizes,  there  will 
alcohol  do  its  paralyzing  work.  He  knew  that  when 
blood  vessels  in  the  liver  are  somewhat  paralyzed  and 


A  DRUNKARD'S  LIVER  RUINED  BY  ALCOHOL 
(After  Horsley) 

enlarged  beyond  their  usual  size,  the  liver  itself  is  sure 
to  suffer  in  a  serious  way. 

When  a  doctor  examines  liver  after  liver  as  he  finds 
them  in  the  hospital  and  in  the  dissecting  room,  he 
counts  the  ignorance  of  the  unfortunate  men  no  laughing 


172        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

matter.  "  A  drunkard's  liver  again,"  he  will  say  as  he 
opens  up  the  telltale  gland.  "  No  wonder  the  man  died. 
It's  a  wonder  he  lived  as  long  as  he  did,  with  a  liver 
of  this  sort  to  purify  his  blood  supply  for  him.  It  has 

swollen  to  twice  its  natural  size. 
The  tubes  are  distended  and  in- 
active ;  the  cells  are  loaded  with 
fat."  Any  such  inactivity  pre- 
pares a  man  to  fall  an  easier 
prey  to  microbe  diseases  and  to 
die  earlier  than  he  might  have 
died.  Life-insurance  societies 
know  this  so  well  that  some  of 
them  charge  even  the  moder- 
ate drinker  more  for  the  same 
amount  of  insurance  than  they 
charge  the  non-drinker. 

The  Kidneys  —  what  they  Are 
and  what  they  Do.  Two  other 
glands  cooperate  with  the  liver 
as  protectors  of  the  body.  These 
are  the  kidneys.  They  lie  on 
each  side  of  the  lower  part  of  the  back,  and  their  struc- 
ture is  a  marvelous  arrangement  of  closely  packed  micro- 
scopic tubes  which  are  netted  about  by  vast  numbers  of 
capillaries.  They  weigh  from  four  to  six  ounces  apiece. 
Their  special  work  is  to  remove  poisons  and  wastes  that 


THE  KIDNEYS  AND   THE   BAG 

WHICH     THEY     SUPPLY     WITH 

WASTE  WATER 

A,   artery ;     B,   vein ;      C,   tube 

through  which  water  leaves  the 

kidney 


LARGE  GLANDS:    THEIR  USE  AND  ABUSE         173 

accumulate  in  the  blood.  All  this  waste  is  then  sent,  as 
a  liquid,  through  two  slender  tubes  into  the  bladder. 
Thence,  by  another  tube,  it  leaves  the  body. 

In  view  of  what  they  do,  the  kidneys  may  well  be 
called  the  life  preservers  of  the  body.  For  after  stomach, 
intestines,  villi,  and  liver  have  done 
what  they  can  for  us,  the  left-over 
wastes  and  poisons  are  finally 
thrown  upon  the  kidneys  for  dis- 
posal. If,  then,  the  kidneys  fail  us, 
the  outlook  for  the  body  is  serious 
indeed.  Brain,  muscles,  glands, 
arteries,  and  veins  will  now  suffer 
because,  one  and  all,  they  draw 
their  supplies  from  an  impure 
blood  stream. 

Effects  of  Alcohol  on  the  Kidneys. 

A    CUT   THROUGH    THE 

When,  therefore,  the  jovial  drinker  KIDNEY 

pours  his  beer  and  his  whiskey  Notice  the  clusters  of  slender 
•  ,  i  •  iiii«  tubes ;  each  separate  one 

into  his  stomach,  let  him  remem-  might  be  called  a  laboratory 
ber  that  the  alcohol  of  that  drink 

will  pass  quickly  into  his  blood,  that  within  a  few  min- 
utes it  will  find  its  way  to  the  cells  and  the  tissues  of 
his  life-preserving  kidneys,  and  that,  in  course  of  time, 
those  tender  tissues  will  become  inflamed  and  less  able 
to  do  even  so  much  as  their  usual  work.  Nevertheless, 
while  in  this  condition,  there  will  pour  upon  them  not  only 


174        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

the  alcoholic  blood  itself  to  be  grappled  with  but  all  the 
unconquered  wastes  and  poisons  which  the  overworked 
liver  could  not  eliminate.  The  struggle  will  keep  on  for 
a  season.  Unpurified  blood  will  grow  more  and  more 
impure,  until  both  the  liver  and  the  kidneys  are  over- 
come at  last.  When  this  happens  the  doctor  may  say: 
"You  are  suffering  from  auto-intoxication.  Your  whole 
system  seems  to  be  out  of  order,  but  the  main  trouble 
is  with  your  liver  and  your  kidneys.  They  seem  to  be 
literally  worn  out." 

Auto-intoxication.  When  a  doctor  speaks  of  auto- 
intoxication-—  and  most  of  them  do  it  nowadays  —  he 
means  that  the  body  is  being  injured  by  poisons  made 
within  itself.  As  it  happens,  a  great  part  of  these  poi- 
sons comes  from  certain  microbes  which  multiply  within 
the  intestine.  Some  of  them  are  really  harmless.  Others 
are  known  as  the  putrefactive  microbes.  They  live 
mostly  on  the  proteid  foods  in  the  intestines,  and  as 
they  multiply  they  produce  poisons  which  in  some  cases 
are  most  detrimental  to  the  body.  Nevertheless,  these 
poisons  —  toxins,  they  are  called  —  are  sucked  up  by 
the  villi  along  with  the  useful  food  and  are  sent  to  the 
liver 'to  be  poured  into  the  general  blood  supply.  Imag- 
ine, then,  the  work  which  is  forced  upon  the  liver  as  it 
tries  to  take  the  toxins  from  the  blood  stream.  What 
the  liver  cannot  attend  to,  the  kidneys  must  remove. 
If  both  these  organs  have  been  damaged  by  alcohol,  or 


LARGE  GLANDS:    THEIR  USE  AND  ABUSE        175 

by  any  other  cause,  they  cannot  do  full  work.  The  blood 
is  then  not  cleared  of  poisons  as  it  should  be,  and  the 
result  is  auto-intoxication.  This  shows  itself  in  headache, 
irritability,  or  discomfort  of  one  sort  or  another.  Serious 
illness  may  follow,  just  because  a  weakened  body  is  at  a 
disadvantage  when  disease  microbes  attack  it : 

How   to   prevent   Auto-intoxication.     There   are   three 
ways  to  prevent  auto-intoxication : 

1.  Be  mindful  of  the  liver  and  the  kidneys  and 
do  not  put  into  the  body  any  food  or  drink  which 
may  weaken  the  power  of  either.    Even  when  these 
organs  are  in  their  best  condition,  they  .have  about 
all  they  can  do  to  save  us  from  auto-intoxication. 
Do  not  lessen  their  power  to  serve  you. 

2.  Avoid  much  animal  pro  teid.  This  decays  faster 
than   vegetable    proteid    in    the    alimentary    canal, 
and  the  faster  the  decay  the  more  the  putrefactive 
microbes  multiply.    Think  how  much  sooner  meat 
spoils  than  beans.    Guard  yourself  against  alcohol, 
against  tea  and  coffee,  and  against  all  highly  sea- 
soned foods.    Also   eat   sparingly  of  the  following 
articles:   pies,  soggy  dumplings,  rich  cake,  dough- 
nuts, and  everything  soaked  in  frying-fat.    All  are 
more  or  less  indigestible.     If  you  ever  eat  them, 
therefore,  do  thorough  chewing  before  the  swallow- 
ing.    Turn   them   into   thin  paste   in  your  mouth. 
When  taken  in  this  condition  they  do  less  harm. 


176        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

3.  Get  rid  of  waste  from  the  large  intestine  every 
day.     Food  waste  should  pass  through  the  entire 
length  of  the  alimentary  canal  within  from  sixteen 
to  twenty  hours  after  it  is  swallowed.     If  waste  is 
not  fully  cleared  away,  it  acts  like  a  poison  to  the 
body.    We  then  say  the  person  is  constipated.    In 
this  condition  the  body  is  threatened,  for  microbes 
in  the  intestine  are  multiplying  in  constantly  swarm- 
ing hosts,  and  auto-intoxication  is  almost  sure  to 
result.    As  a  rule  take  no  medicine  for  constipation. 
Instead,  take  regular  exercises  that  make  the  mus- 
cles of  the  abdomen  work  hard,  and  eat  graham  or 
bran  bread  —  or  even  a  tablespoonful  of  bran  itself 
—  with  every  meal.    One   may  buy  this  from  any 
grocer.    Bran  helps  by  giving  bulk  for  the  intestine 
to  act  upon.     Eat  freely  of  lettuce,  celery,  vegeta- 
bles, and  fruit.    Be  sure  to  drink  the  needed  three 
pints  of  water  every  day. 

4.  Avoid  tainted  food.   So-called  ptomaine  poison- 
ing often  follows  the  eating  of  tainted  meats.    And 
thousands  of   babies  die   because  their  milk   food 
is  spoiled  by  microbes.     This  is  why  we  insist  on 
having  fresh  meat  and  clean  milk. 

Headache  and  Auto-intoxication.  It  should  be  stated 
clearly  that  headache  is  more  often  due  to  auto- 
intoxication than  to  any  other  one  cause.  (Headache 
from  eyestrain  is  spoken  of  later.)  To  get  rid  of  the 


LARGE  GLANDS:    THEIR  USE  AND  ABUSE        177 

pain,  clear  the  body  of  its  waste.  Also,  for  immediate 
relief,  wrap  a  hot,  wet  towel  about  the  face  and  the 
back  of  the  neck.  This  expands  the  capillaries  and 
draws  blood  from  the  brain.  Never  take  drugs  unless 
everything  else  fails  and  the  doctor  orders  it.  The  drug 
habit  is  easily  formed,  and  it  is  a  fearful  master. 

Other  Glands.  The  same  damaged  blood  which  ham- 
pers the  liver  and  the  kidneys,  giving  us  headache  and 
other  ills,  is  also  a  disadvantage  to  every  other  gland  of 
the  body.  Each  is  a  mass  of  soft  tissue  made  up  of 
separate  working  cells.  In  size  our  glands  vary  all  the 
way  from  the  four-pound  liver  to  the  smallest  sweat 
gland  in  the  skin.  The  product  of  any  gland  is  called 
its  secretion.  Some  glands  send  their  secretion  through 
a  duct  to  its  destination.  For  example,  the  surface  of 
the  body  receives  sweat  secretion  from  the  sweat  glands. 
The  eyeball  receives  a  secretion  from  the  lachrymal 
glands.  Five  other  sets  of  glands  —  about  which  we 
have  already  studied  —  send  their  secretions  into  the 
alimentary  canal.  Still  other  glands  are  called  ductless. 
These  ductless  glands  send  their  secretion  directly  into 
the  blood  as  it  passes  through  them.  They  have  no  need 
of  any  duct.  Nevertheless,  what  they  manufacture  is  of 
vital  importance  to  the  body.  Among  ductless  glands 
are  the  two  thyroids  in  the  neck.  When  these  are  dis- 
eased, people  often  suffer  from  what  is  known  as  goiter. 
But  whether  glands  have  ducts  or  not,  a  damaged  blood 


178        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

supply  is  a  disadvantage  to  them  all.    This  is  part  of 
the  reason  why  tight  clothing  is  so  objectionable. 

Ill  Effects  of  Snug  Garments.    The  fashion  for  small 
waists   comes   and    goes,   but    harm   comes    and    stays 

even  when  the  pres- 
sure of  the  lacing 
is  not  very  great. 
Imagine  some  new 
kind  of  X  ray  that 
could  show  what  lac- 
ing does  to  different 
parts  of  the  body. 
Here  are  the  items 
of  damage: 

i.  The  liver 
is  forced  into 
such  small  com- 
pass that  its  cap- 
illaries and  tiny 
tubes  are  hard- 
pressed  upon. 
Thus  crowded 
they  cannot  do 

good  work  in  preparing  needed  glycogen  for  the 
body.  Neither  can  they  fully  purify  venous  blood 
of  its  waste.  As  a  result,  unpurified  blood  goes  on 
its -way,  carrying  danger  to  all  parts  of  the  body. 


INSIDE  ORGANS  BEFORE  THE  LACING 


LARGE  GLANDS:    THEIR  USE  AND  ABUSE         179 

2.  The  stomach  is  so  crumpled  up  and  crowded 
that  indigestion  follows,  than  which  nothing  is  more 
fatal  to  a  beautiful  complexion. 

3.  The    long   folds    of    the    small    intestine   are 
pushed  downward,  and  are  so  pressed  upon  that  the 
entire  tube  becomes 

inactive.  Food  moves 
slowly  through  it, 
and  as  this  food  de- 
cays, gas  is  formed 
and  toxins  multiply. 
This  gas  stretches 
the  walls  of  stomach 
and  intestine  alike, 
and  pain  follows. 

4.  After  lacing  has 
gone    on    for    some 
time     the     muscles 

which   make   up   the      RIBS  OF  A  YOUNG  WOMAN  WHO  DIED  AT 

walls  of  the  abdo- 
men become  relaxed 
and  flabby  through  lack  of  exercise.  As  a  result, 
the  organs  which  these  muscles  should  hold  in  place 
are  left  sagging  downward.  After  this  each  organ 
has  to  carry  on  its  business  as  best  it  can  under 
most  unfavorable  conditions.  If  illness  follows,  the 
suffering  person  should  blame  no  one  but  herself. 


THE  AGE  OF  TWENTY-THREE.  SHE  LACED 
(After  Tracy) 


l8o       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

5.  Lacing  so  cramps  the  lower  lung  cells  that  mul- 
titudes of  air  sacs  are  wholly  out  of  service  and 
breathing  has  to  be  done  through  the  lifting  of  the 
chest  —  not  through  the  better  way  of  spreading  out 
the  ribs.    How  loose  then  should  our  clothing  be  ? 
Importance  of  Loose  Clothing.    Stand  with  your  back 
to  the  wall,  with  head,  heels,  and  elbows  touching  it. 

Now  draw  a  deep  breath. 
Can  you  do  this  without 
feeling  that  bands,  strings, 
buttons,  or  hooks  are  be- 
ing pulled  rather  vigor- 
ously ?  Our  clothing 
should  always  be  loose 
enough  to  allow  us  to 
breathe  freely.  Bands 
should  never  bind  the 
waist,  and  the  weight  of 
heavy  clothing  should  be 
carried  by  straps  that 

THE  SHAPE  THE  RIBS  SHOULD  HAVE        hang   frQm    ^    shoulders> 

Remember  that  the  more  easily  the  gland  laboratories 
are  allowed  to  do  their  work,  the  better  able  are  we 
to  endure  the  wear  and  tear  of  life  and  to  resist  disease 
of  every  sort. 

The  Two  Body  Cavities.    In  a  way  it  may  be  hard  to 
think  of  the  trunk  of  the  body  as  a  double-story  set  of 


THE  DIAPHRAGM  WHEN  IT  is  RELAXED 
The  organs  from  above  it  and  below  it  have  been  removed 

181 


182        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

apartments,  but  such  it  is.  For,  stretching  across  us  from 
side  to  side,  a  little  above  the  waistline,  is  a  strong,  broad, 
elastic  partition  of  muscle,  called  the  diaphragm.  Below 
it,  in  one  cavity,  lie  liver,  stomach,  intestine,  and  other 


EXERCISES  TO  STRENGTHEN  THE  MUSCLES  OF  THE  ABDOMINAL  WALL 
(After  Schmidt) 

important  organs;  above  it,  in  another  cavity,  are  the 
heart  and  lungs,  with  the  large  and  small  tubes  which 
belong  to  them.  Through  the  diaphragm  go  a  large 
artery,  a  large  vein,  and  the  tube  which  carries  food 
from  the  mouth  to  the  stomach. 


LARGE  GLANDS:  THEIR  USE  AND  ABUSE    183 

Above  the  diaphragm,  then,  we  find  the  organs  of 
respiration  and  circulation ;  below  it  lie  the  organs  of 
digestion  and  the  great  gland,  the  liver.  Above  the 
diaphragm,  blood  is  ridding  itself  of  carbon  dioxide ; 
below  the  diaphragm,  blood  is  getting  supplies  of 
nourishment  to  carry  to  the  tissues  of  the  entire  body. 

The  Rhythmic  Movement  of  the  Diaphragm.  But  what 
active  share  does  the  diaphragm  take  in  all  this  ?  Draw 
a  deep  breath.  As  you  do  this,  you  are  not  only 
raising  your  ribs  but  also  contracting  your  diaphragm 
from  every  side,  taking  the  arched  shape  out  of  it, 
and  forcing  it  down  upon  the  organs  below.  Each 
breath  gives  those  lower  organs  good  exercise,  for  the 
diaphragm  is  the  largest  and  the  strongest  breathing- 
muscle  we  have.  When  it  contracts,  air  rushes  down 
into  the  lungs.  When  it  relaxes  into  its  normal  arched 
shape  the  pressure  is  lifted,  air  rushes  out  of  the  lungs, 
and  the  upper  cavity  is  smaller  again. 

Liver,  stomach,  and  intestines  all  gain  vigor  from 
the  rhythmic  movement. 

Aid  to  the  Organs  of  Excretion.  The  rhythmic  move- 
ment is  important  because  our  organs  of  excretion  need 
the  exercise  that  it  gives  them.  These  organs  are  the 
lungs,  which  get  rid  of  carbon  dioxide;  the  small  and 
large  intestines,  which  rid  us  of  food  waste ;  and  the  kid- 
neys, which  rid  us  of  waste  water  and  its  poisons.  The 
skin  is  the  fourth  great  organ  of  excretion.  It  helps  the 


1 84        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

kidneys  through  its  discharge  of  perspiration  and  will 
be  discussed  later. 

Notice  the  difference  between  excretion  and  secre- 
tion. Excretion  is  waste  from  the  body.  Secretion  is 
something  manufactured  by  an  organ  of  the  body. 

QUESTIONS 

1.  Name  the  largest  gland  in  the  body.  2.  Give  its  position;  its 
weight.  3.  Mention  its  three  kinds  of  work.  4.  Through  what  duct 
does  bile  go  to  the  small  intestine?  5.  What  kind  of  waste  goes  into 
the  bile  ?  6.  Why  does  the  liver  store  up  certain  substances  in  its 
own  cells?  7.  When  it  cannot  store  it  all,  what  becomes  of  the  rest? 

8.  What  does  a  doctor  advise  men  to  do  when  they  have  liver  trouble  ? 

9.  Why  is  a  piece  of  raw  liver  bloody  ?    10.  Why  is  alcohol  especially 
harmful  to  the  liver?     11.  What  often  happens  to  the  liver  through 
the  use  of  alcohol?     12.  What  do   life-insurance   societies   do   about 
charging  drinkers  for  their  insurance  ? 

13.  What  other  glands  are  greatly  affected  by  alcohol?  14.  Give 
the  location  of  the  kidneys;  their  appearance;  their  weight.  15.  What 
is  their  special  work?  16.  Where  do  they  send  their  waste?  17.  If 
they  fail  in  their  work,  what  parts  of  the  body  will  surfer?  Why? 

18.  Mention  facts  which   those   who    use    alcohol   should   remember. 

19.  Besides  alcohol,  what  other  substances  will  reach  the  kidneys  in 
the  blood  stream  ?    20.  When  liver  and  kidneys  are  overcome,  what 
will  the  doctor  probably  say? 

21.  What  is  meant  by  auto-intoxication?  22.  What  are  putrefactive 
microbes  ?  23.  Where  do  they  multiply  ?  24.  What  do  the  villi  do  with 
the  toxin  which  the  putrefactive  microbes  manufacture?  25.  What  does 
the  liver  do  with  these  toxins  when  they  reach  it  ?  26.  If  the  liver  can- 
not take  them  all  out  of  the  blood,  what  must  the  kidneys  do?  27.  If 
both  the  liver  and  the  kidneys  have  been  damaged  by  alcohol,  or  by  any 


LARGE  GLANDS:    THEIR  USE  AND  ABUSE        185 

other  cause,  what  happens  to  the  blood  ?  28.  Mention  three  ways  by 
means  of  which  one  can  prevent  auto-intoxication.  29.  Why  is  it  neces- 
sary to  keep  the  body  well  cleared  of  its  waste  substances  ?  30.  How 
much  water  should  we  drink  each  day?  31.  Which  decays  faster  in 
the  alimentary  canal,  animal  proteid  or  vegetable  proteid  ?  32.  Why 
should  we  reduce  our  supply  of  animal  proteid  ? 

33.  What  are  the  manufacturing  organs  of  the  body  ?  34.  What  is 
the  structure  of  each  gland  ?  35.  How  do  they  vary  in  size  ?  36.  What 
is  the  product  of  a  gland  called?  37.  Mention  different  ways  in  which 
glands  send  off  their  secretion.  38.  What  secretion,  from  what  glands, 
is  poured  out  on  the  surface  of  the  body?  39.  What  glands  supply 
the  eyeball  with  moisture  ?  40.  How  many  sets  of  glands  send  their 
secretions  into  the  alimentary  canal?  41.  What  are  ductless  glands? 
42.  How  does  their  secretion  get  into  the  blood  ?  43.  When  thyroid 
glands  are  diseased,  what  is  the  name  of  the  disease  ? 

44.  What  happens  to  the  liver  when  a  person  laces?  45.  What  is 
the  effect  of  lacing  on  the  stomach  ?  on  digestion  ?  46.  How  does 
lacing  hinder  the  work  of  the  small  intestine?  47.  Why  do  the  walls 
of  the  abdomen  become  relaxed  and  flabby  ?  48.  Is  this  an  advantage 
or  a  disadvantage  to  the  work  of  the  internal  organs  ?  49.  What  does 
lacing  do  to  the  lower  lung  cells  ?  50.  What  is  the  diaphragm  ? 
51.  What  organs  are  above  the  diaphragm?  below  it?  52.  When 
relaxed,  what  shape  does  it  take  and  what  happens  to  the  air  in  the 
lungs  ?  53.  Name  the  organs  of  excretion.  54.  Define  excretion ; 
secretion.  55.  How  loose  should  clothes  be  about  the  waist?  56.  If 
gland  laboratories  and  the  diaphragm  are  allowed  to  do  their  work 
freely,  what  will  be  the  result  to  the  body? 


CHAPTER  XIII 

WHY  NATIONS   RID  THEMSELVES  OF  ALCOHOL 

France  and  the  Liquor  Problem.  On  the  eighteenth  of 
December,  1902,  in  the  city  of  Paris,  France,  a  report 
was  made  by  a  committee  of  the  government.  The  state 
officials  considered  this  report  so  valuable  that  they 
ordered  copies  of  it  to  be  printed  as  posters  in  large 
black  letters  on  a  white  background. 

These  posters  were  placarded  here  and  there  on  the 
important  buildings  of  the  city.  They  were  put  on  the 
walls  and  in  the  corridors  of  hospitals,  on  the  streets, 
in  the  post  offices,  and  even  on  the  outside  wall  of  the 
great  Hotel  de  Ville,  where  the  business  of  the  city 
is  carried  on. 

A  few  extracts  will  show  what  it  was  that  the  govern- 
ment wished  to  proclaim  in  this  public  way. 


DRAFTED   BY 

PROFESSOR  DEBOVE,  Dean  of  the  Faculty  of  Medicine 
DR.  FAISANS,  Physician  to  the  Hotel  Dieu 

Alcoholism  is  chronic  poisoning,  resulting  from  the  habitual  use  of 
alcohol,  even  when  this  is  not  taken  in  amounts  sufficient  to  produce 
drunkenness.  Alcohol  is  useful  to  nobody,  it  is  harmful  to  all.  It  leads, 

186 


WHY  NATIONS  RID  THEMSELVES  OF  ALCOHOL      187 

at  the  very  least,  to  the  hospital,  for  alcoholism  causes  a  great  variety 
of  diseases,  many  of  them  most  deadly.  It  is  one  of  the  most  frequent 
causes  of  consumption.  Typhoid  fever,  pneumonia,  or  erysipelas,  which 
would  be  mild  in  a  sober  individual,  will  rapidly  kill  the  alcoholic. 
Alcoholism  is  one  of  the  most  frightful  scourges,  whether  it  be  re- 
garded from  the  point  of  view  of  the  health  of  the  individual,  of  the 
existence  of  the  family,  or  of  the  future  of  the  country. 

After  the  beginning  of  the  great  war  in  1914  France 
went  even  further,  and  absolutely  prohibited  the  manu- 
facture and  sale  of  the  intoxicant,  absinth. 

The  German  Attitude.  Nor  does  France  stand  alone  in 
this  protest.  Even  as  long  ago  as  1908  Germany  had 
already  printed  871  books  that  discussed  the  question  of 
alcohol.  At  that  time  37  German  newspapers,  maga- 
zines, and  annuals  devoted  themselves  to  the  same  sub- 
ject, and  hundreds  of  articles  about  alcohol  were  printed 
in  the  important  magazines  of  that  country.  In  1907 
one  hundred  leading  professors  in  German  universities 
signed  a  declaration  which  included  the  following 
statements : 

All  prevalent  ideas  in  regard  to  the  invigorating  and  otherwise  sup- 
posedly beneficial  properties  of  alcohol  in  small  doses  have  been  proved 
erroneous  by  scientific  research.  Moderate  drinking  has  a  tendency  to 
make  the  human  body  more  liable  to  disease  and  to  shorten  life. 

With  this  testimony  before  them,  we  are  not  surprised 
to  learn  that  in  1915  — for  the  sake  of  guarding  German 
soldiers  and  German  workmen  from  inefficiency  —  the 
supply  of  beer  in  Germany  was  cut  down  60  per  cent 


1 88        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Russia  and  Prohibition.  In  Russia,  in  1914,  when  the 
war  began,  orders  were  issued  that  thenceforth  there 
should  be  absolute  prohibition  of  alcoholic  drinks.  This 
meant  that  in  a  country  where  150,000,000  people  had 
been  using  all  the  liquor  they  cared  to  pay  for,  no  more 
should  be  either  manufactured,  bought,  or  sold.  In  de- 
scribing what  was  done,  Professor  Helenius  Sepala  of 
the  University  of  Helsingfors,  Finland,  says: 

On  the  sixteenth  of  October,  1914,  all  the  old  stock  of  ale  in  the  beer 
shops  was,  by  order  of  the  authorities,  poured  out  on  the  ground.  .  .  . 
Everywhere  in  Russia,  including  Siberia,  the  Caucasian  provinces,  Cour- 
land,  etc.,  the  sale  of  distilled  liquors  and  strong  wines  is  strictly  pro- 
hibited. ...  I  walked  about  the  capital  one  day  after  another,  stepping 
into  restaurants  both  in  main  streets  and  in  side  lanes,  and  feeling  like  a 
dreamer  because  the  sights  I  had  formerly  seen  everywhere  in  the 
Russian  capital  I  now  no  longer  saw.  ...  I  did  not  see  drunken  men 
and  women,  I  did  not  find  whiskey  or  vodka  anywhere.  There  were 
great  festivals  going  on,  the  streets  were  filled  with  people  overpowered 
by  their  patriotic  emotions,  it  being  the  birthday  of  the  czarevitch,  but 
all  the  time  I  did  not  see  a  single  person  the  worse  for  liquor. 

Another  writer  says : 

On  account  of  this  prohibition,  crimes  have  diminished  so  much  in 
Russia  that  the  planned  building  of  new  prisons  has  had  to  be  inter- 
rupted. Physicians  tell  us  that  the  number  of  patients  in  the  hospitals 
has  decreased  considerably  and  that  the  alcoholistic  polyclinics  in  Petro- 
grad  are  now  practically  without  anything  to  do !  On  the  other  hand, 
the  officials  of  the  savings  banks  have  been  compelled  to  ask  for  increase 
of  their  number,  in  some  places  double,  on  account  of  too  much  work, 
and  the  number  of  depositors  has,  in  spite  of  the  war  times  and  unusual 
difficulties,-  increased  enormously. 


WHY  NATIONS  RID  THEMSELVES  OF  ALCOHOL      189 

The  English  Method.  In  England  they  are  trying  to 
reduce  the  consumption  of  liquor  by  greatly  increasing 
the  taxes  on  it  and  by  giving  the  government  full  power 
to  control  the  saloons  in  places  where  war  material  is 
being  produced  and  transport  work  done. 

The  Japanese  Liquor  Law.  In  Japan  the  law  of  the 
land  forbids  the  sale  of  alcoholic  drinks  to  those  who 
are  under  twenty  years  of  age. 

The  Movement  in  America.  In  the  United  States  of 
America,  in  1915,  520  daily  newspapers  and  63  impor- 
tant magazines  refused  to  print  any  advertisement  of 
whisky,  beer,  or  other  alcoholic  beverage,  and  the  num- 
ber of  such  papers  increases  with  each  month.  These 
statistics  were  gathered  by  the  Temperance  Society  of 
the  Methodist  Church. 

In  1915  the  new  rule  of  the  Carnegie  Steel  Works, 
Pittsburgh,  Pennsylvania,  declared  that  promotion  was 
only  for  total  abstainers.  In  1915,  also,  the  head  of 
the  Health  Department  of  New  York  City  declared 
that  the  entire  power  of  the  board  would  be  used 
to  "fight  the  rich  man's  champagne  as  well  as  the 
poor  man's  beer."  The  statement  was  then  made 
that  "it  is  as  necessary  to  battle  drink  as  to  fight  an 
epidemic." 

The  United  States  Department  of  Labor  has  investi- 
gated the  subject  of  alcohol  in  connection  with  the  em- 
ployers of  skilled  labor.  It  finds  that  already  72  per 


190       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

cent  of  the  farmers,  88  per  cent  of  the  trades,  and 
90  per  cent  of  the  railroads  make  positive  discrimi- 
nation against  the  man  who  uses  alcohol.  For  ex- 
ample, Marshall  Field  and  Company,  of  Chicago,  say: 
"  Any  man  in  our  employ  who  acquires  the  habit  of  drink, 
even  though  moderately,  is  to  a  certain  extent  marked 
down  in  our  estimation,  and  unless  we  can  remove  from 
him  this  serious  fault  and  show  him  his  error,  we  feel 
compelled  to  do  without  his  services."  Employers  of 
labor  discriminate  in  this  way  because  they  cannot 
afford  to  pay  for  the  services  of  a  man  who  is  below  par 
physically  and  mentally. 

And  what  of  skilled  laborers  themselves?  On  May  25, 
1915,  in  Cleveland,  Ohio,  the  Brotherhood  of  Locomotive 
Engineers  passed  the  following  resolution  by  unanimous 
vote :  "  Be  it  resolved  that  this  Brotherhood  of  Locomo- 
tive Engineers  go  on  record  as  favoring  state-wide  and 
nation-wide  prohibition  of  intoxicating  beverages."  There 
were  present  819  delegates,  who  represented  74,000  engi- 
neers in  all  parts  of  the  United  States  and  Canada.  After- 
wards one  of  them  said :  "  Engineers  of  America  have 
been  trained  for  years  to  understand  that  drink  and 
efficiency  do  not  run  hand  in  hand.  If  any  one  needs  a 
clear  head  it  is  the  man  in  the  cab." 

Nor  is  this  all.  Great  nations  and  great  bodies  of 
voters  are  not  the  only  ones  who  are  voting  themselves 
free.  Smaller  nations  are  equally  anxious  for  safety. 


WHY  NATIONS  RID  THEMSELVES  OF  ALCOHOL      191 

The  Island  of  Newfoundland.  During  December,  1915, 
Newfoundland  voted  four  to  one  in  favor  of  prohibition 
for  the  entire  island.  The  count  stood  24,965  votes  for 
prohibition  and  5348  votes  against  it. 

Taxes,  Crime,  and  Poverty.  No  doubt  thousands  of 
citizens  in  every  land  have  in  mind  the  taxes  which  they 
must  pay  to  help  support  the  poorhouse,  the  courthouse 
and  jail,  the  reformatory,  the  insane  asylum,  the  orphans' 
home,  and  the  police  force  of  every  state  and  city.  In  these 
days  we  all  know  that  the  larger  part  of  the  occupants  of 
these  institutions  are  where  they  are  because  they  them- 
selves or  their  ancestors  used  alcohol  as  a  beverage.  Mr. 
Henry  M.  Boies,  who  studied  the  subject  for  years  in 
America,  said  that  the  crime  committed  in  the  United 
States  costs  at  the  rate  of  $6.20  a  year  for  each  man, 
woman,  and  child  in  our  country,  and  that  alcohol's  share 
in  the  expense  of  this  crime  is  about  $4.34  for  each 
person.  Drunkenness  alone,  he  tells  us,  costs  the  United 
States  $420,000,000  a  year. 

Statistics  for  London,  England,  show  that  this  one  city 
pays  $5,000,000  a  year  for  the  expense  of  its  drunken 
paupers. 

To  show  the  difference  which  alcohol  makes  in  the 
taxes  of  license  and  no-license  towns,  glance  at  the  fol- 
lowing figures.  They  are  compiled  from  the  reports  of 
the  United  States  Bureau  of  the  Census  on  municipal 
revenue  expenditures  and  public  property  for  1913. 


192        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

GENERAL  PROPERTY  TAXES  COLLECTED 

Prohibition  states $10.12  per  capita 

Near-prohibition  states $  11.08  per  capita 

Partially  license  states $14.32  per  capita 

License  states $16.98  per  capita 

When  you  see  a  drunken  man  arrested,  or  read  of  men 
taken  to  jail  or  to  the  hospital  because  they  have  dam- 
aged themselves  or  other  people  by  using  alcohol,  you 
might  say  to  yourself,  "  My  honest,  hard-working  father, 
through  his  taxes,  helps  pay  for  arresting  the  man,  for 
trying  him,  for  taking  care  of  him  in  prison,  for  feeding 
and  clothing  him  while  he  is  there ;  and  if  the  man 
dies  in  the  place,  my  father  must  help  meet  the  bill  for 
his  burial." 

Fortunately  the  entire  world  is  wakening  to  the  serious 
harm  which  alcohol  does  to  society  in  every  way,  and 
this  explains  the  dawning  era  of  prohibition. 

QUESTIONS 

1.  Tell  how  Paris  began  to  attack  its  liquor  problem.  2.  When  did 
France  prohibit  the  manufacture  and  sale  of  absinth  ?  3.  What  had 
Germany  done  before  1908  about  the  alcohol  question?  4.  What  decla- 
ration did  the  leading  professors  of  Germany  make  ?  5.  How  much  was 
Germany's  beer  supply  cut  down  in  1915  ?  6.  What  orders  were  issued 
in  Russia  in  1914?  7.  How  many  people  did  these  orders  affect? 

8.  What  did  Professor  Sepala  say  about  the  results  of  this  action? 

9.  What  effect  did  prohibition  have  on  prison  building?  on  the  number 
of  patients  in  the  hospitals  ?    10.  What  did  England  do  to  reduce  liquor 


WHY  NATIONS  RID  THEMSELVES  OF  ALCOHOL      193 

consumption  ?  11.  What  is  the  liquor  law  in  Japan  ?  12.  Tell  what  you 
can  about  liquor  advertisements  in  papers  and  magazines  in  the  United 
States  in  1915. 

13.  Give  the  rule  of  the  Carnegie  Steel  Works  about  promotion. 
14.  When  the  United  States  Department  of  Labor  investigated  the  sub- 
ject of  alcohol  in  connection  with  the  employers  of  skilled  labor,  what 
did  it  find?  15.  Why  do  employers  of  labor  object  to  those  who  use 
alcohol  ?  16.  Give  the  resolution  of  the  Brotherhood  of  Locomotive 
Engineers.  17.  What  was  the  result  of  the  vote  on  prohibition  in 
Newfoundland  ?  18.  Why  are  taxes  high  in  countries  that  use  alcohol  ? 
19.  W7hat  sends  many  people  to  the  poorhouse,  the  jail,  the  insane 
asylum,  and  the  orphans'  home  ?  20.  Give  Mr.  Boies'  statement  about 
the  cost  of  crime  in  the  United  States.  21.  What  is  London's  annual 
expense  for  drunken  paupers  ?  22.  What  is  the  difference  between  prop- 
erty taxes  in  prohibition  states  and  in  license  states  ?  23.  In  what  way 
does  every  honest  man  help  support  those  who  are  criminals  and  worthless  ? 


CHAPTER  XIV 

BODY  TEMPERATURE  AND  THE  SKIN;  OR  WORK, 
HEAT,  AND  FUEL 

Testing  the  Effect  of  Heat  on  the  Body.  There  is  no 
doubt  about  the  value  of  the  work  which  certain  scien- 
tists did  in  1775.  These  men  were  anxious  to  know  how 
much  heat  the  body  of  man  can  endure  and  still  keep  at 
its  work.  For  the  sake  of  making  no  great  blunder,  they 
began  their  tests  by  passing  from  one  heated  room  to 
another  until  they  found  themselves  living  and  breath- 
ing in  a  room  in  which  the  thermometer  showed  a  heat 
of  210°  F.  This  is  but  two  degrees  cooler  than  the 
temperature  which  water  needs  for  boiling. 

As  may  be  imagined,  the  air  of  the  room  felt  very 
hot.  One  man,  however,  stayed  in  it  for  ten  minutes. 
During  this  time  the  heat  was  so  great  that  it  twisted 
and  broke  the  ivory  frames  of  all  the  thermometers  but 
one.  More  than  this,  the  air  which  the  man  inhaled  was 
so  much  hotter  than  that  which  he  exhaled,  that  with 
each  breath  which  he  drew  he  felt  as  if  he  were  scorch- 
ing his  nostrils.  But  with  each  exhalation  his  nostrils 
were  cooled  again.  He  took  the  thermometer  in  his 

hand  and  blew  on  it.    At  once  the  mercury  sank  in  the 

194 


BODY  TEMPERATURE  AND  THE  SKIN     195 

tube,  showing  that  his  breath  was  cooler  than  the  room. 
He  blew  on  his  fingers,  and  they  were  cooled  too. 

In  another  experiment,  afterwards,  the  same  men  went 
into  a  small  room  which  was  even  hotter  than  any 
they  had  been  in  before.  Here  the  thermometer  showed 
260°  F.  This,  then,  was  forty-eight  degrees  hotter  than 
water  needs  for  boiling.  As  they  entered  the  air  felt 
hot,  but  they  could  bear  it.  And  while  they  stayed  there, 
they  did  various  things  to  show  what  the  heat  of  the 
room  was  able  to  accomplish.  They  took  a  piece  of  raw 
beefsteak,  left  it  uncovered,  took  a  pair  of  bellows,  blew 
the  heated  air  across  the  steak  for  thirteen  minutes, 
and  found  that  it  was  rather  overcooked.  An  egg  was 
roasted  hard  in  twenty  minutes;  water  soon  boiled  and 
bubbled;  watch  chains  became  too  hot  to  be  touched; 
and  rings  had  to  be  left  off,  lest  the  heated  metal  should 
burn  a  deep  circle  about  the  tender  flesh  of  the  finger. 
Leather  shoes  could  not  be  worn,  for  the  leather  itself 
curled  up  and  was  ruined. 

Sweat  Glands  as  Protectors.  All  this  happened  to 
their  possessions,  but  the  men  themselves,  although 
surrounded  by  the  same  heated  air,  were  neither  boiled 
nor  roasted.  They  lived  and  breathed  in  the  place, 
escaped  alive,  and  their  escape  was  no  miracle.  It  was 
explained  by  the  power  of  the  sweat  glands.  If  these 
small  laboratories  had  stayed  inactive  the  scientists 
might  have  suffered  from  the  heat  even  as  did  the  steak. 


196        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

As  soon  as  the  men  entered  the  heated  room  the 
sweat  glands  began  their  work  and  perspiration  was  manu- 
factured in  quantities;  it  poured  from  the  open  flues  of 
countless  small  laboratories  and  emptied  itself  upon  the 
skin,  whence  it  was  evaporated.  Thus 
perspiration  kept  the  skin  moist,  and  the 
evaporation  of  the  moisture  kept  the  sur- 
face of  the  body  cool  enough  to  save  it 
from  being  cooked.  Certainly  the  men 
were  uncomfortable  from  first  to  last,  but 
they  did  not  suffer. 

The  record  of  these  experiments  is 
given  in  the  Philosophical  Transactions 
of  the  Royal  Society  of  London  for  the 
year  1775. 

If  you  ever  have  the  chance,  watch  the 
streaming,  steaming  backs  of  such  men 
as  pitch  coal  into  the  huge  furnace  of  an 
A  SWEAT  GLAND  ocean  liner.  There  you  will  see  the  same 
AND  ITS  OUTLET  WOrk  of  protection  carried  on  by  these 

ON  THE  SKIN  .  r  J  . 

tireless  glands.  Their  exact  number  is 
unknown,  but  by  counting  a  few  in  a  small  area  of  the 
skin,  and  by  multiplying  this  number  by  the  extent  of 
the  surface  of  the  body,  men  estimate  that  each  of  us  is 
supplied  with  about  2,000,000  sweat-gland  laboratories. 
All  are  slightly  busy  most  of  the  time,  but  are  only  ex- 
traordinarily busy  when  emergencies  overtake  the  body* 


BODY  TEMPERATURE  AND  THE  SKIN 


197 


Important   Facts    about   the    Skin, 
your  knowledge  of  the  skin  and  of 

1.  The   outside    layer   of   the 
skin  is  called  epidermis.     It  can 
be  cut  or  pricked  without  giving 
pain.      It  protects   all   that   lies 
underneath    it,    in    the    second 
layer   of   the    skin. 

2.  The  second  layer  —  the  der- 
mis  —  holds  countless  capillaries, 
also  nerve  fibers,  hair  cells  with 
their    muscles    and    oil    glands, 
sweat  glands,  and  pigment  cells. 
These  last  contain  coloring  mat- 
ter —  pigment  —  which  gives  one 
boy  freckles  and  another  boy  tan  ; 
which  makes  one  man  brown  and 
another  man  yellow.     Both  nails 
and    hair    are    constantly   being 
formed  in  the  dermis  and  pushed 
upward.1 

3.  Perspiration  is  a  mixture  of 
water  and  waste.     It   is  poured 
out  by  the  sweat  glands  when  the 
body  is  heated  or  exercised.  The 

1  Full  directions  about  the  care  of  both  are  given 
in  Health  and  Safety. 


Just   here,    review 
perspiration. 


CUT  THROUGH  THE 
LAYERS  OF  THE  SKIN 

A,  horny  layer  of  epider- 
mis ;  B,  deeper  layer  of 
epidermis ;  C,  duct  of 
sweat  gland ;  D,  dermis ; 
E)  connective  tissue  in 
which  the  black  lines  rep- 
resent blood  vessels 


198        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

water  soon  evaporates  and  cools  the  skin.  The 
waste  stays  on  the  skin  and  must  be  washed  or 
rubbed  off;  otherwise  it  mixes  with  oil  from  the 
oil  glands,  with  bits  of  epidermis,  with  dust  from 
the  clothes  and  from  the  air,  and  stays  like  a  snug, 
thin,  perfectly  fitting  coat  on  the  outside  of  the 
body  from  head  to  heel.  A  wrap  of  this  sort  inter- 
feres with  the  healthy  action  of  the  skin  and  gives 
off  an  unpleasant  smell.  It  may  be  removed  by  a 
hard,  dry  rub,  and  it  is  important  to  take  the  rub 
whenever  a  bath  is  out  of  the  question. 
What  the  Skin  Does.  The  skin  does  four  most  impor- 
tant things  for  us. 

1.  It  covers  the   body  as  a  wrapping  without  a 
break  in  it.    Thus  it  keeps  multitudes  of  microbes 
from  entering.    When  a  patch   of  skin   is   entirely 
destroyed  by  being  scalded  or  burned,  there  is  such 
power  of  life  left  along  the  edges  that  new  skin 
grows  out  from  it  day  by  day  until  the  chasm  is 
entirely  covered  —  provided  it  is  not  too  large.    If 
it  is  too  large,  doctors  step  in  with  their  wonderful 
help  from  grafted  skin.    By  what  they  do  they  may 
save  the  person  from  being  badly  scarred. 

2.  By  means  of  its  sweat  glands  it  helps  regulate 
the  heat  of  the  body  and  keeps  it  at  uniform  tem- 
perature throughout  life.    No  device  of  nature  is  of 
more  practical  service  to  us. 


BODY  TEMPERATURE  AND  THE  SKIN     199 

3.  It  forms  the  ground  against  which  nerves  act 
and  through  which  we  do  our  feeling.    Most  of  our 
impressions  of  heat  and  cold,  of  pain  and  suffering, 
reach  us  through  the  skin. 

4.  It  helps  the  lungs  and  the  kidneys  in  their 
work  of  sending  waste  from  the  body.    Perspiration 
is  waste  matter  that  is  being  eliminated. 

For  each  of  us,  however,  there  is  something  far  more 
important  than  hot  ovens,  burned  flesh,  and  the  graft- 
ing of  the  skin.  It  is  not  probable  that  we  ourselves 
shall  meet  these  terrible  experiences.  For  us  a  practical 
everyday  danger  is  always  at  hand. 

Taking  Cold.  We  may  take  cold  through  our  igno- 
rance of  the  laws  that  govern  the  health  and  vigor  of  the 
skin.  Let  us  therefore  remember  that  the  skin  is  con- 
stantly covered  with  a  slight  moisture  called  insensible 
perspiration,  and  that  when  there  is  enough  of  this 
moisture  to  be  noticed  it  is  called  sensible  perspiration. 
One  advantage  of  perspiration  is  that  it  cools  the  body 
whenever  it  is  in  danger  of  getting  overheated.  For 
the  sake  of  grasping  the  situation  more  clearly,  bear  the 
following  facts  in  mind : 

1.  When  a  man  is  heated  from  exercise,  capillaries 
in  the  exercised  part  of  the  body  are  stretched  out 
with  the  blood  which  is  forced  into  them. 

2.  If  a  heated  man,  covered  with  perspiration,  sits 
in  a  draft,  his  blood  is  cooled,  the  capillaries  of  the 


200       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

skin  contract,  and  the  mass  of  the  blood  goes  to 
some  other  place. 

3.  When  this  occurs,  the  linings  of  nose,  throat, 
lungs,  and  intestines  are  apt  to  be  overcrowded  by 
the  blood  which  has  been  forced  into  them  from  the 
skin,  and  the  most  sensitive  lining  suffers  most. 
Symptoms  of  a  Cold.    Usually  the  first  symptom  is  that 
a  man  feels  stuffy  in  nose,  throat,  or  lungs.   The  explana- 
tion of  .the  feeling  is  the  distended  capillaries  and  the 
condition  of  the  blood  itself.    Although  red  corpuscles 
continue  to  deal  with  oxygen  as  they  have  always  done, 
still  the  white  corpuscles  are  now  behaving  strangely. 
They  get   together,  many  of  them  stick  to  the  inside 
walls  all  along  the  length  of  the  capillaries,  and  the  more 
inactive  they  are,  the   less  do  they  seize  and  destroy 
intruding  microbes.    These  microbes,  therefore,  remain 
uncaptured    in    the    blood  and  continue  such  mischief 
as  their  nature  makes  possible. 

When  a  man  has  a  cold,  the  trouble  often  is  that 
influenza  microbes  have  escaped  the  white  corpuscles 
and  have  firmly  established  themselves  in  the  part  of 
the  body  which  is  congested  with  blood. 

In  view  of  these  facts  it  is  not  hard  to  understand  why 
a  man  who  has  a  cold  is  so  much  more  liable  to  take 
other  diseases  to  which  he  is  exposed.  He  is  in  a  weak- 
ened condition,  and  already  microbes  instead  of  white 
corpuscles  have  the  upper  hand  in  his  body. 


BODY  TEMPERATURE  AND  THE  SKIN     20 1 

But  suppose  a  cold  is  coming  on,  what  does  our  knowl- 
edge of  the  laws  of  the  skin  direct  us  to  do  about  it  ? 

To  Check  a  Cold.  Draw  blood  away  from  the  region  of 
the  cold  as  promptly  as  possible.  Do  it  in  several  ways : 
take  vigorous  exercise  until  every  sweat  gland  is  active ; 
take  a  hot  bath;  soak  the  feet  in  hot  water;  drink  hot 
lemonade;  go  to  bed;  sleep  warm;  perspire  freely.  By 
keeping  warm  in  bed,  the  blood  goes  to  the  surface  of 
the  body,  and  delicate  internal  membranes  are  relieved 
of  superfluous  blood.  White  corpuscles  are  also  stirred 
up,  and  restoration  begins.  Stay  in  bed  until  the  feeling 
of  cold  is  over.  One  night  may  suffice.  When  you  leave 
the  bed,  wipe  off  with  warm  water,  then  take  a  quick 
wash  with  cool  water.  This  will  stimulate  the  nerves 
of  your  skin  without  chilling  the  blood  itself,  and  will 
keep  you  from  taking  cold  afterwards. 

To  Prevent  a  Cold.  Here  are  three  rules  of  prevention 
that  you  should  remember: 

1.  Never  sit  in  a  room  that  feels  chilly.    A  long 
slow  chilling  of  the  body  does  even   more   harm 
than  a  draft. 

2.  Never  come  in  heated  from  hard  exercise  and 
cool  off  in  a  chilly  room.    Multitudes  of  colds  are 
taken  in  this  way.    Either  continue  to  exercise  in  the 
room,  or  wrap  up  thoroughly.    Best  of  all,  take  a 
quick,  cool  bath  in  a  warm  room  and  change  your 
damp  underwear  before  you  sit  down. 


202        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

3.  Remember  that  there  is  little  danger  of  harm 
to  health,  however  damp  the  clothing  may  be,  so 
long  as  vigorous  exercise  is  kept  up. 

4.  Obey  all  the  general  laws  of  eating,  exercise, 
etc.,  and  follow  the  instructions  on  page  207  about 
educating  the  body  to  adjust  itself. 

The  reason  for  all  this  is  that  bodies  are  provided 
with  the  extraordinary  power  of  regulating  their  own 
temperature  by  means  of  fuel  and  work. 

Internal  Temperature.  Let  a  man  live  in  central  Africa 
or  let  him  travel  to  the  coldest  land ;  let  him  stay  in 
the  burning  heat  of  his  city  home  or  wander  in  the 
cool  shadows  of  the  country;  let  him  be  in  bed  or  in 
the  harvest  field,  in  the  countinghouse  or  in  the  mine; 
wherever  he  is,  he  will  find  that,  if  he  is  well,  a  ther- 
mometer placed  under  his  tongue  always  indicates  about 
ninety-eight  degrees  of  heat.  This  is  what  we  call  normal 
temperature. 

In  each  place,  also,  even  if  he  is  not  well,  the  heat  of 
his  body  will  change  but  little.  We  say  that  a  man  has  a 
slight  fever  if  his  temperature  is  100°  F.  If  it  reaches 
102°,  we  grow  somewhat  troubled;  if  it  rises  to  103°  and 
then  to  104°,  we  are  truly  anxious;  for  no  man  is  ex- 
pected to  live  after  his  temperature  has  reached  a  higher 
point  than  107°. 

It  is  well  for  us  that  the  body  has  this  power  to  keep 
the  blood  warm  independent  of  outside  conditions ;  for  if 


BODY  TEMPERATURE  AND  THE  SKIN  203 

it  were  otherwise,  —  if  we  were  as  cold-blooded  as  is  the 
frog,  —  we  should  be  as  useless  in  cold  weather  and  in 
cold  places  as  he  is.  We  should  have  to  hibernate  in 
winter  as  he  does. 

Warm-blooded  Animals.  Birds,  as  well  as  all  animals 
that  begin  life  by  taking  milk  from  their  parents  —  mam- 
mals they  are  called  —  are  warm-blooded.  Each  has  for 
itself  this  wonderful  power  of  meeting  the  changes  of 
the  weather  with  a  constant  temperature  of  its  own.  As 
a  result,  such  animals  are  generally  warmer  than  the  sur- 
rounding air  and  are  called  warm-blooded  for  this  reason. 

Cold-blooded  creatures  usually  feel  cold  to  the  hand 
when  we,  who  are  warm-blooded,  touch  them.  Their 
bodies  have  no  power  to  stay  warm  when  the  air  is 
cold  about  them. 

Although  we  have  this  power,  it  is  nevertheless  true 
that  even  the  heat  of  our  warm  bodies  can  fail.  Men  do 
freeze  to  death.  They  cannot  be  frozen  almost  solid  and 
then  thaw  out  again  and  live,  as  certain  frogs  have  been 
known  to  do.  People  may  live  in  the  coldest  countries 
and  be  active  and  healthy  there,  but  the  one  condition 
is  that  they  help  the  body  do  its  work  by  preventing  the 
escape  of  more  heat  than  the  same  body  can  promptly 
replace.  Never  confuse  these  two  facts : 

i.  During  health  the  inside  heat  of  the  body 
changes  little  from  year's  end  to  year's  end.  If  it 
changes  many  degrees  up  or  down,  we  die. 


204       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

2.  The  skin  feels  warm  or  cold  as  the  air  about  it 
changes.  Skin  and  nose  and  toes  may  freeze,  but  the 
inside  temperature  remains  practically  unchanged. 
Why  Clothes  are  Needed.  Put  a  dozen  people  in  a 
small  room,  and  the  room  grows  warmer  because 
those  human  beings  give  off  enough  heat  to  warm 
the  air  about  them.  In  a  cold  country  or  in  a  cold 
room  each  body  must  keep  within  itself  as  much  of 
its  own  heat  as  it  can.  Naturally,  therefore,  we  wear 
more  clothes  at  one  time  than  at  another.  We  are 
treasuring  up  our  own  supply  of  heat  for  our  own 
use,  and  we  know  that  we  lose  this  heat  largely  from 
the  surface  of  the  body  —  from  the  skin.  We  there- 
fore wrap  up.  Do  not  forget  that  we  are  warmed  not 
by  the  cold  we  keep  out  but  by  the  heat  we  keep  in.1 
Flannel  succeeds  better  than  cotton  in  preventing  the 
escape  of  heat,  because  more  air  is  entangled  in  the 
mesh  of  woolen  goods  than  in  a  cotton  fabric.  This  air 
keeps  the  heat  from  passing  from  the  body,  because  air 
is  what  is  known  as  a  poor  conductor  of  heat.  For  this 
reason  we  choose  woolen  goods  for  winter  wear  and 
cotton  materials  for  summer. 

1  If  the  body  is  not  sufficiently  covered,  heat  radiates  from  it  and  escapes. 
Cool  air  takes  its  place  at  once  and  surrounds  the  body  as  a  layer.  Capillaries  in 
the  skin  now  contract  and  force  the  blood  away  from  the  surface  to  the  inward 
parts  of  the  body.  These  parts  then  become  congested,  while  the  skin  feels  cold, 
because  the  contracted  blood  vessels  can  only  hold  a  small  supply  of  blood.  By 
putting  on  extra  clothing  and  by  rubbing  the  body  hard,  we  cause  blood  vessels 
in  the  skin  to  expand,  more  blood  passes  through  them,  and  we  are  warm  again. 


BODY  TEMPERATURE  AND  THE  SKIN     205 

Moreover,  each  additional  layer  of  clothing  means 
an  extra  jacket  of  air  underneath  it.  And  since  air  is 
a  poor  conductor  of  heat,  several  layers  of  thin  gar- 
ments—  with  their  separate  layers  of  air  between  them 
—  are  often  a  warmer  protection  than  one  thicker 
garment  with  its  one  layer  of  air  underneath. 

In  summer  we  choose  the  thinnest  clothing  and  the 
fewest  possible  layers  of  it.  We  wish  to  make  it 
easy  for  heat  to  escape.  Nor  is  clothing  our  only 
warming  device. 

Warmth  through  Exercise.  Why  do  boys  say,  "  It's 
so  cold  we  Ve  got  to  run  to  keep  warm "  ?  For  this 
reason  —  when  muscles  contract  and  when  blood  moves 
fast,  the  heat  of  the  body  is  decidedly  increased.  Vigor- 
ous exercise  of  large  muscles  increases  the  heat  of  the 
blood.  Then,  as  this  blood  reaches  the  skin,  it  is  cooled 
by  the  evaporation  of  the  perspiration.  Our  body  has 
two  ways  by  means  of  which  it  controls  heat  escape: 

1.  By  regulating  the  flow  of  blood  into  the  skin. 

2.  By  the  sweat  glands  and  what  they  do. 
Food  as  Fuel.    Consider  that  while  you  exercise  you 

breathe  hard  and  expel  warm  air  from  your  lungs. 
This  comes  from  heat  produced  by  your  body  while 
it  works.  And  what  is  the  source  of  its  power  both 
to  work  and  to  produce  heat?  Watch  yourself  at  the 
dinner  table  after  exercising.  You  have  such  an  appe- 
tite as  comes  only  when  you  have  been  using  up 


206        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

your  supplies.  Food  is  to  the  body  what  fuel  is  to  a 
stove,  and  in  a  certain  way  your  machine  has  been 
burning  up  its  fuel  while  you  worked  and  grew  warm. 
Your  appetite  is  nature's  call  for  a  fresh  supply  of  food. 

Sometimes  active  exercise  leads  the  body  to  call  for 
so  much  fuel  that  the  stored-up  supply  —  fat  —  is  rapidly 
reduced.  Any  football  player  will  tell  you  that  during 
the  football  season  he  loses  fat  which  he  gained  during 
the  previous  summer. 

To  Reduce  Fat.  The  body  has  need  of  extra  fuel  when 
it  does  unusual  work,  and  it  then  draws  on  its  reserved 
supply.  A  fat  man  applies  this  power  of  the  body  to  his 
own  case.  He  studies  himself  both  in  the  mirror  and  on 
the  scales  and  concludes  that  his  body  has  stored  up  too 
much  fuel  in  the  shape  of  fat.  He  knows  that  to  get  rid 
of  it  he  must  use  it,  and  at  once  he  begins  a  course  of 
vigorous  exercise  which  gives  hard  work  to  large  mus- 
cles. They  respond  by  calling  for  fuel,  and  if  he  is  faithful 
day  after  day,  the  mirror  and  the  scales  will  soon  show 
that  he  is  accomplishing  his  purpose  —  that  he  is  losing 
his  fat. 

Perhaps  we  wonder  how  it  happens  that  although  we 
sometimes  exercise  so  hard  as  to  use  up  much  of  our 
fuel,  the  thermometer  shows  a  gain  of  so  little  bodily 
heat.  As  we  already  know,  the  reason  rests  partly  with 
the  sweat  glands.  They  are  such  a  successful  cooling 
device  that  whenever  we  exercise  enough  to  raise  our 


BODY  TEMPERATURE  AND  THE  SKIN  207 

temperature  above  its  normal  point,  they  promptly  manu- 
facture their  clear-colored  liquid.  And  when  once  manu- 
factured, they  send  so  much  of  it  out  upon  the  skin  to 
evaporate  there  that,  no  matter  how  warm  we  feel,  the 
internal  temperature  of  the  body  is  kept  from  rising 
too  high  for  safety. 

The  body  is  thus  seen  to  produce  its  own  heat,  while  it 
also  cools  itself  when  we  overheat  it.  Through  this  power, 
however,  we  may  take  cold  unless  we  know  how  to  pre- 
vent heat  from  escaping  too  fast  when  the  body  needs  it. 

Educating  the  Body  to  Adjust  Itself.  We  may  so  train 
the  body  that  it  will  increase  its  power  to  adjust  itself 
to  different  states  of  heat  and  cold.  In  other  words,  the 
body  can  be  educated.  This  may  be  done  by  following 
the  rules  about  eating  and  exercise  already  given  and  by 
attending  to  a  few  other  points. 

1.  Do  not  spend  much  time  in  overheated  rooms, 
that  is,  in  places  heated  above   70°  F.    The  body 
grows    exceedingly   sensitive    to   cold  *  if   it   is   kept 
constantly  too  warm. 

2.  Do  not  overweight  yourself  with  clothing  in 
a  warm  house  or  take  vigorous  exercise  in  heavy 
garments.    In  other  words,  regulate  your  clothes  to 
your  need. 

3.  If  you  are  in  good  health,  take  a  quick  cold 
bath  every  morning.    Nothing  is  better  for  prepar- 
ing the  blood  vessels  for  changes  in  temperature. 


208        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Don't  run  about  with  bare  feet  and  get  chilled  be- 
fore this  early  bath.  The  body  should  be  warm  for  it. 
Never  give  a  cold  body  a  cold  bath.  Never  take  a  cold 
bath  in  a  cold  room.  Let  the  room  be  as  warm  as 
70°.  It  may  be  even  warmer.  Let  the  cold  bath  be 
short  —  one  minute  is  long  enough.  You  are  using 
the  water  for  a  tonic,  not  for  a  scrub.  Use  two 
rough  towels,  one  wet  and  one  dry.  Wet  face  and 
neck  first,  then  arms,  chest,  abdomen,  back,  legs,  and 
feet.  If  you  have  no  bathtub  or  shower  bath,  take 
a  washbowl  of  water,  and  wash  and  wipe  one  part  of 
the  body  after  the  other  quickly  in  the  order  given. 
(The  shower  bath  also  goes  from  the  neck  down- 
wards.) Waste  no  time.  Rub  fast  and  hard  until  the 
skin  is  pink.  The  body  will  glow  with  a  feeling  of 
warmth  and  vigor.  If  it  does  not  glow, — if  it  is  cold 
instead,  —  then  you  are  not  quite  vigorous  enough 
to  take  the  cold  bath.  You  must  get  stronger  first. 

4.  Keep  the  body  clean  by  taking  a  soap-and- 
water  bath  at  least  once  a  week. 
He  who  attends  to  the  various  rules  connected  with 
bathing,  eating,  exercise,  and  the  heating  of  the  body 
will  find  at  last  that  he  has  reached  the  happy  condition 
where  sudden  changes  in  temperature  and  unexpected 
drafts  do  not  harm  him  as  they  did  in  former  days. 

We  see,  then,  that  the  real  purpose  of  hygiene  is  to 
help  the  body  as  it  tries  to  help  itself.    In  reality,  food, 


BODY  TEMPERATURE  AND  THE  SKIN     209 

muscles,  blood  vessels,  and  sweat  glands  work  together 
for  the  regulation  of  body  temperature.  At  the  same 
time  the  central  regulator  of  all  their  activity  is  the 
nervous  system.  To  this  we  now  turn  our  attention. 

QUESTIONS 

1.  What  were  scientists  trying  to  learn  about  the  heat  of  the  body 
In  1775  ?  2.  Describe  the  way  they  tested  the  human  body  in  heated 
rooms.  3.  How  hot  was  the  air?  4.  What  happened  to  beefsteak, 
•eggs,  water,  and  watch  chains  that  were  in  the  same  room?  5.  How 
did  the  men  feel?  6.  What  saved  them  from  being  cooked?  7.  When 
are  the  sweat  glands  most  active?  8.  How  many  sweat  glands  is  a 
human  being  supposed  to  have  ?  9.  Describe  the  epidermis.  10.  De- 
scribe the  dermis  and  tell  what  is  in  it.  11.  Describe  perspiration. 

12.  What  things  are  mixed  with  perspiration  on  an  unwashed  skin? 

13.  What  four  things  does  the  skin  do  for  us?    14.  From  what  part 
does  new  skin  grow  to   cover  a  wound?     15.  When  is  skin-grafting 
necessary  ? 

16.  What  is  insensible  perspiration?  17.  What  is  sensible  perspira- 
tion ?  18.  What  is  the  purpose  of  perspiration  ?  19.  When  a  man  is 
heated,  what  happens  to  the  capillaries  ?  20.  If  he  sits  in  a  draft,  what 
then  ?  21.  What  is  generally  the  first  symptom  of  a  cold  ?  22.  Describe 
the  behavior  of  the  white  blood  corpuscles  at  such  times.  23.  Why  is  a 
man  who  has  a  cold  more  liable  to  take  other  diseases  ?  24.  If  you  feel 
a  cold  coming  on,  what  should  you  do  to  check  it  ?  25.  Give  three  rules 
for  preventing  colds.  26.  What  can  you  say  about  the  heat  of  the  body 
in  different  countries?  27.  What  is  our  normal  temperature?  28.  De- 
scribe warm-blooded  and  cold-blooded  creatures.  29.  What  can  you  say 
about  the  inside  heat  of  the  body  ?  30.  Why  does  a  room  grow  warmer 
when  people  are  in  it?  31.  Why  should  we  wear  more  clothes  at  one 
time  than  at  another?  32.  From  what  part  of  the  body  do  we  lose 
heat?  33.  Why  is  flannel  warmer  than  cotton  clothing?  Why  are 


210       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

several  layers  useful?    34.  Are  we  warmed  by  the  cold  we  keep  out 
or  by  the  heat  we  keep  in  ? 

35.  How  does  exercise  keep  us  warm  ?  36.  In  what  two  ways  does 
the  body  control  the  escape  of  heat?  37.  What  connection  is  there 
between  food  and  the  power  of  the  body  to  heat  itself  by  exercise  ? 

38.  When  much  exercise  is  taken,  what  stored-up  fuel  is  drawn  upon  ? 

39.  What  may  a  fat  person  do  to  change  his  appearance  ?  40.  How  can 
you  explain  the  fact  that  hard  exercise  has  little  effect  on  the  inside 
temperature  of  the  body  ?   41.  Since  the  body  can  cool  itself  when  it 
is  too  warm,  what  is  the  danger  in  being  overheated?    42.  Give  four 
rules  for  helping  the  body  to  adjust  itself  to  heat  and  cold.    43.  What 
is  the  real  purpose  of  hygiene  ? 


CHAPTER  XV 
THE  NERVOUS  SYSTEM 

The  Value  of  Sensations.  If  a  cat  felt  no  unpleasant 
sensation  when  he  needed  food,  he  would  never  bestir 
himself  from  a  comfortable  nap  for  the  sake  of  eating. 
If  a  mouse  felt  no  unpleasant  sensation  when  the  claws 
of  a  hungry  cat  were  hooked  into  his  skin  to  seize  him, 
he  might  allow  himself  to  be  caught  and  eaten  without 
a  struggle.  If  human  beings  felt  no  discomfort  in  the 
coldest  weather,  they  might  carelessly  let  themselves 
be  frozen  to  death. 

The  Hedge  of  Nerve  Warnings.  So  it  is  on  every  side. 
All  along  the  way  we  go,  our  sensations  are  our  best 
protectors.  Indeed,  during  each  day  of  our  lives  our 
animal  kindred  and  we  ourselves  travel  through  life 
over  a  road  that  is  guarded  on  either  side  by  what 
might  seem  to  be  a  hedge  of  nerve  warnings  called 
sensations.  The  sensations  themselves  are  of  various 
kinds,  hunger  and  thirst,  cold  and  heat,  headache,  tooth- 
ache, stomach  ache  —  ills  of  many  different  sorts.  But 
through  each  separate  one  we  learn  at  last  that  by 
giving  heed  to  our  sensations  —  to  those  that  are 


211 


212        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


ONE  SET  OF  FIBERS  AT  WORK 


disagreeable  as  well  as  to  those  that  are  agreeable  —  we 

do  much  to  preserve  our  health  and  to  make  the  path- 
way of  life  safe  and 
delightful. 

What  Nerves  are.  Be- 
fore the  microscope  was 
invented  even  the  very 
wisest  men  had  to  do 
much  of  their  scien- 
tific work  by  guessing. 
They  imagined  that 
each  nerve  was  a  tube 

filled    with    something    exceedingly    fine    and    delicate 

called  animal  spirits.    But  in  recent  times,  guessing  has 

been  discarded.  For  the 

microscope  shows  that 

nerves   are    not    tubes 

at  all.  Instead  they  are 

a  system  of  fine  fibers 

which  carry  stimuli  and 

messages     back     and 

forth  between  the  other 

parts     of     the      body 

and  the  brain.    These 

fibers  look  like  slender 

threads.    They  run  from  the  brain  to  the  spinal  cord, 

from  the  cord  to  the  muscles,  then  from  the  muscles  up 


ANOTHER  SET  OF  FIBERS  AT  WORK 


THE  NERVOUS  SYSTEM  213 

again  to  the  spinal  cord  and  the  brain.  Just  under  the 
skin  these  fibers  cover  the  body  in  a  close  network,  and 
it  is  through  their  aid  that  living  beings  feel,  and  move, 
and  control  their  actions. 

Work  of  the  Fibers.  More  than  this,  it  is  well  to  know 
that  nerve  fibers  are  divided  into  two  groups  which  do 
two  kinds  of  work.  One  group  carries  stimuli  to  the 
brain  from  skin,  eye,  ear,  nose,  tongue,  and  from  all  the 
internal  organs  of  the  body.  These  are  called  sensory 
nerves.  The  other  group  carries  commands  from  the 
brain  to  every  point  in  the  body  that  needs  directing. 
These  are  the  motor  nerves. 

When  a  baby  sees  a  flame,  laughs  with  joy,  thrusts 
his  fingers  into  it,  and  pulls  them  out  again  with  a 
scream,  several  sets  of  fibers  have  been  at  work. 

1.  One  set,  from  the  eyes,  helped  the  brain  to  see 
a  lovely  color. 

2.  Another  set  brought  word  from  the  brain  to 
the  muscles  of  the  hand,  "  Feel  it." 

3.  A  third  set  carried  a  stimulus   to  the   brain, 
which    seemed    to    say,    "  Something    dreadful    is 
happening   to    the    fingers." 

4.  A  fourth  set  brought  the  prompt   command, 
"  Pull    the    fingers    out    of    the    color  as    fast    as 
possible." 

Different  Sets  of  Fibers.  In  the  meantime  other  groups 
of  fibers  set  other  muscles  to  work,  so  that  at  one  point 


214        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

the  baby  opened  its  mouth  to  laugh  with  joy  and  a 
moment  later  opened  it  again  to  scream  with  pain.  Still 
other  fibers  commanded  the  heart  to  pump  faster  and 
send  more  blood  to  the  excited  head.  They  commanded 
the  tear  glands  to  manufacture  salt  water  with  incredi- 
ble speed  and  in  great  abundance.  They  set  lungs  and 
vocal  cords  to  work,  too.  And  as  the  result  of  so  much 
stimulation  sent  up  to  the  brain  and  so  many  commands 
sent  down  from  the  brain,  we  end  with  a  nervously 
exhausted,  screaming,  red-faced,  tear-stained  baby,  rather 
a  dejected-looking  piece  of  living  machinery. 

Stimuli.  If  we  could  ever  follow  any  series  of  mes- 
sages up  and  down,  we  should  learn  to  understand  how 
swift  their  flight  is.  Stimuli  from  remote  regions  of  the 
body  fly  upward  to  the  brain,  and  there,  in  what  is  really 
the  great  central  station,  the  various  kinds  are  recog- 
nized and  attended  to.  Commands  are  issued  at  once, 
and  each  of  these  now  goes  by  its  own  road  downward 
to  the  spinal  cord.  From  there  it  is  flashed  across  an 
unbroken  long-extended  fiber  to  a  toe,  or  a  finger  tip,  or 
to  any  muscle  of  the  body  that  is  to  be  controlled  by  it. 

The  longest  fibers  are  those  which  carry  an  impulse 
from  the  toe  up  into  the  spinal  cord  and  those  which 
bring  commands  back  over  the  same  distance.  In  a  tall 
man  these  fibers,  carrying  messages  in  one  direction  or 
the  other,  may  be  four  or  five  feet  long.  And  their  work 
is  as  perfect  as  that  of  any  short  fiber. 


THE  NERVOUS  SYSTEM 


215 


Distribution  of  Nerves.  If  by  any  clever  process  we 
could  separate  the  nerves  of  a  man  from  the  rest  of  his 
body,  if  we  could  turn  each  one  of  these  nerves  into 
something  stiff  and  firm, 
and  then  could  stand  the 
entire  group  on  a  pedestal 
in  precisely  the  shape  which 
it  had  when  it  did  its  work 
in  the  body,  we  should  un- 
derstand better  than  we  do 
the  marvel  of  its  structure. 
This  network  of  stiff  nerves 
would  be  so  delicate  and 
so  closely  woven  together 
that  we  should  be  able  to 
follow  perfectly  the  outline 
of  the  man  to  whom  it  be- 
longed. We  should  know 
his  height,  the  breadth  of 
his  shoulders,  the  size  of 
head,  hands,  and  feet ;  while 
at  the  same  time  we  should 
note  that  on  certain  parts 
of  his  skin  the  network  was  specially  fine  and  delicate. 

If,  going  further,  we  should  cut  that  nerve  figure 
open,  we  should  find  other  great  clusters  of  nerves  that 
showed  the  outline  of  every  separate  organ  of  the  body. 


NERVES  THAT  SHOW  THE  OUTLINE  OF 
THE  HUMAN  BODY 


2l6        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Having  seen  all  this,  unless  we  know  the  facts  of  the 
case,  we  might  give  a  thousand  wild  guesses  as  to  what 
this  wilderness  of  nerves  was  for  and  how  it  was  ever 
able  to  control  the  sensations  and  the  movements  of  a 
human  being.  Some  knowledge  of  the  working  of  the 
brain  will  help  explain  the  difficulty  to  us. 

Memory  and  the  Cerebrum.  Dr.  W.  H.  Ho  well,  in  his 
physiology,  describes  the  case  of  a  dog  who  met  with  mis- 
fortune, lost  the  upper  part  of  his  brain,  —  the  cerebrum, 
as  it  is  called,  —  and  led  a  singular  life  ever  afterwards. 

Those  who  were  studying  the  case  kept  the  dog  alive 
a  year  and  a  half,  and  they  saw  that  although  the  animal 
did  not  suffer  actual  pain,  still  he  did  not  know  enough 
to  feed  himself ;  he  did  not  even  recognize  his  food  when 
he  saw  it;  he  showed  no  pleasure  when  caressed  nor 
any  fear  when  threatened.  Not  a  trick  that  he  had  ever 
learned  did  he  now  remember.  And  as  for  burying 
bones  for  future  use,  there  was  no  thought  of  such  a 
thing.  Indeed,  from  the  moment  he  lost  his  cerebrum, 
until  he  died,  he  seemed  to  do  no  thinking  whatever. 
Memory  was  so  entirely  gone  that  he  recalled  nothing 
that  he  had  ever  learned.  Formerly  he  had  been  a 
clever  and  sprightly  dog,  remembering  old  tricks,  learn- 
ing new  ones,  stealing  bones  and  burying  them,  frighten- 
ing cats,  loving  his  friends,  and  fighting  his  foes;  but 
from  the  moment  he  lost  his  cerebrum  all  was  changed. 
Henceforward  he  was  dull,  inactive,  and  uninteresting. 


THE  NERVOUS   SYSTEM 


217 


In  man  the  cerebrum  is  even  more  important  He 
may  lose  part  of  it  through  disease  or  accident  and  still 
be  able  to  live  and  think,  but  if  he  loses  the  whole  of 
it,  he  dies.  If  it  is  injured  he  suffers  in  various  ways. 
It  is  the  region  of 
the  brain  that  is 
most  vitally  con- 
nected with  our 
thinking,  with  our 
activity,  and  with 
our  power  to  judge 
what  is  best  for 
ourselves. 

This  constantly 
active  and  most  im- 
portant part  of  the 
nervous  system  lies 
just  under  the  skull. 
It  is  the  largest  di- 
vision of  the  brain, 
and  is  separated 
into  two  halves  called  hemispheres,  as  shown  above. 

Structure  of  the  Brain.  If  you  ever  have  a  chance,  take 
in  your  hands  a  human  brain  that  has  been  preserved 
in  alcohol  and  let  a  doctor  describe  it  to  you.  First  of 
all,  however,  you  will  notice  that  the  substance  itself 
looks  like  nothing  so  much  as  a  neatly  folded,  closely 


THE  HEMISPHERES  OF  MAN'S  CEREBRUM, 
THE  CENTER  OF  CONTROL 


•2 1 8        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

packed  mass  of  gray  putty,  so  lifeless  and  so  uninterest- 
ing that  you  may  feel  like  exclaiming:  "  Is  this  the  great 
commander  in  chief  .of  the  body  of  man !  Is  this  queer- 
looking  stuff  the  basis  of  all  my  thinking  and  my 
feeling !  " 

But  let  the  doctor  hold  it  and  explain  it  to  you 
part  by  part.  Watch  his  eyes;  listen  to  his  voice  as 
he  does  it;  for  they  will  tell  you  that  to  him  this 
lifeless  mass  is  interesting  in  every  smallest  division. 
He  will  press  one  part  away  from  another  at  the 
surface,  and  you  will  see  that  although  each  can  be 
separated  slightly  from  its  neighbor,  still  all  are 
firmly  held  together  at  the  center. 

He  will  show  you  the  cerebrum  and  another  division, 
called  the  cerebellum,  and  will  probably  mention  them 
in  that  order,  for  the  cerebrum  is  larger  and  higher  up 
—  a  soft  gray  cap,  it  seems  to  be,  folded  closely  in  deep 
creases,  overlapping  everything  below  it.  Nevertheless, 
the  cerebellum  is  in  sight  just  beneath,  at  the  back  of 
the  head.  It  too  is  folded  and  wrinkled  and  gray. 

Cerebrum,  Cerebellum,  and  their  Convolutions.  It  may 
be  that  you  will  ask  some  questions  about  these  deep 
creases  in  both  cerebrum  and  cerebellum,  —  convolu- 
tions, they  are  called,  —  and  it  may  be  that  the  doctor 
will  answer  very  thoughtfully,  "  The  more  wrinkles,  the 
more  wits,"  for  that  states  the  case  concisely.  "  But 
what  good  do  the  convolutions  do  ? "  you  ask  again. 


THE  NERVOUS   SYSTEM  219 

"  Give  more  surface  for  the  gray  stuff  to  be  spread 
over," 'comes  back  the  answer,  quick  and  positive.  And 
this  answer  leads  the  doctor  up  to  the  point  of  his 
greatest  enthusiasm,  the  gray  substance  of  the  brain. 


A    CUT  THROUGH   THE   BRAIN 

A,  B,  C,  D,  L  show  folds  in  the  cerebrum ;  £,  F  show  the  gray  and  white  of 
the  cerebellum ;  A",  H  show  the  upper  divisions  of  the  spinal  cord 

The  Gray  and  the  White  Brain  Stuff.  Gray  substance 
is  all  you  have  seen  thus  far,  for  it  bends  in  and  out 
with  every  fold  and  crease  as  if  the  whole  substance  of 
the  brain  were  solid  gray.  "  But  look  here,"  exclaims 
the  doctor,  as  he  presses  open  a  deep  cut  which  he 
has  made  with  his  knife  through  the  gray  cap,  "  see 


220       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

how  little  gray  there  really  is  —  only  an  outside  layer 
about  an  eighth  of  an  inch  thick  and  thinner  than 
that  in  spots.  But  every  thought  you  have,  every 
pain  you  feel,  every  plan  you  make,  every  hope  that 
thrills  you,  every  purpose  and  ambition  of  your  life, 
is  intimately  connected  with  this  thin  gray  layer  that 
covers  the  white  substance  below  it." 

While  you  are  thinking  this  over  in  amazement  he 
will  probably  go  on  to  say  that  the  injury  or  disease 
of  any  part  of  that  gray  layer  of  the  brain  may  rob 
you  of  one  sense  or  another,  or  even  destroy  your 
brain  power  in  the  very  direction  where  you  thought 
you  were  strongest. 

Centers  in  the  Cerebrum.  "  If  this  particular  brain  had 
been  injured  here,"  the  doctor  will  say,  pointing  to  a  cer- 
tain spot  on  the  gray  surface,  "  its  owner  would  not  have 
been  able  to  recognize  anything  that  the  eye  looked  at. 
And  this  is  the  worst  sort  of  blindness,  for  when  the 
sight  center  of  the  cerebrum  is  gone  a  man  cannot  so 
much  as  remember  what  seeing  was  like." 

Accidents  to  the  brain  have  taught  some  of  these 
facts;  diseases  of  the  brain  have  taught  others;  while 
the  study  of  the  brains  of  animals  has  let  in  a  flood 
of  light  on  the  whole  subject.  So  that  at  the  present 
time  scientists  know  that  a  definite  part  of  the  gray 
layer  is  active  for  each  separate  sensation  and  for 
the  power  to  move  each  separate  part  of  the  body. 


THE  NERVOUS  SYSTEM 


221 


How  the  Skull  protects  the  Cortex.  This  layer  is  called 
the  cortex,  and  cortex  means  "bark."  It  is  clear  then  that 
the  gray  bark  that  covers  both  cerebrum  and  cerebellum 
is  the  most  precious 
part  of  the  human 
body.  For  this  reason 
it  needs  a  stout  pro- 
tection, and  it  gets  it 
in  the  firmly  knit, 
sturdy  skull  which 
surrounds  it. 

Instead  of  being  a 
snug  fit  in  its  case, 
the  brain  is  separated 
from  the  skull  by  a 
little  space  filled  with 
liquid.  And  it  is  this 
well-housed  brain  that 
controls  the  nerve 
machinery  of  the  body. 

Nerve  Machinery. 
From  what  seems  to  be  RoADS  To  AND  FROM  THE  CORTEX 

a    Confused     tangle    Of      Sight,  hearing,  and  touch  have  special  centers, 

fibers  under  the  skin,  but  taste  and  smdl  are  near  together 

we  might  imagine  that  messages  would  sometimes  get 
lost  on  their  journey — that  those  intended  for  one  partic- 
ular spot  might  find  themselves  delivered  at  the  wrong 


222        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

place,  bringing  despair  to  the  brain.  But  this  never  hap- 
pens. The  confusion  is  only  apparent ;  it  is  caused  by  the 
way  the  bundles  of  fibers  are  variously  bound  together. 
If  we  had  eyes  keen  enough  to  see  the  fibers  them- 
selves, instruments  delicate  enough  to  do  the  work,  and 
hands  steady  enough  to  use  the  instruments  without 
tearing  the  fibers,  we  might  unwrap  them,  bundle  after 
bundle,  and  trace  them  from  start  to  finish.  We  should 

then  find  that  every 
white  nerve  is  a  bun- 
dle of  nerve  fibers, 
each  one  of  which 
is  neatly  and  snugly 
wrapped  by  a  fatty 

NERVE  FIBERS  THAT  END  IN  MUSCLE  ,  , 

covering  that   makes 

it  look  white.  We  should  also  find  that  the  difference 
between  large  nerves  and  small  nerves  is  quite  the  same 
as  the  difference  between  large  bundles  and  small 
bundles  of  telephone  wires,  for  in  each  the  number  of 
separate  strands  explains  the  size. 

Spinal  Nerves.  As  we  studied  the  nerves  in  this  way, 
we  should  discover  for  ourselves  where  the  largest  ones 
are  and  how  they  are  related  to  the  backbone.  We 
should  see  that  the  bones  of  the  back  are  so  ingeniously 
locked  together  that  a  round  opening  is  left  on  each  side 
of  each  pair  of  vertebras,  and  that  as  there  are  thirty-one 
vertebrae  there  must  be  sixty-two  openings  in  all.  We 


THE  NERVOUS   SYSTEM  223 

should  then  notice  that  the  largest  nerves  of  the  entire 
nervous  system  are  these  sixty-two  spinal  nerves  which 
find  their  way  to  the  body  through  the  backbone,  and 
we  should  see  that  as  soon  as  each  leaves  the  bone  the 
dividing  begins.  Large  bundles,  from  the  cord,  become 
smaller  by  dividing,  then  still  smaller.  They  hold  any- 
where from  two  hundred  to  twelve  hundred  separate 
fibers,  and  as  they  continue  to  divide  and  subdivide 
they  branch  in  different  directions  until  fibers  which 
started  in  the  same  bundle  are  widely  separated. 

Often  these  fibers  pass  out  of  the  wrappings  of  one 
bundle  into  the  wrappings  of  another.  They  do  this  so 
constantly  that  the  various  bundles,  as  they  grow  smaller, 
are  joined  together  in  an  intricate  network.  They  twine 
and  intertwine,  but  not  a  fiber  loses  its  way.  Each 
tiny  one  of  the  millions  that  form  the  lacework  of  fibers 
is  a  continuous  path  from  some  definite  point  on  the 
skin,  or  from  some  muscle  or  gland,  to  some  definite 
point  in  the  spinal  cord ;  and  as  long  as  no  accident  or 
wound  cuts  the  nerve  in  two,  the  stimulus  which  each 
may  receive  will  travel  swift  and  true  from  the  point 
of  the  body  where  that  fiber  is  stimulated  to  the  spinal 
cord,  which  will  send  the  impulse  on  to  the  brain  by 
other  fibers. 

What  Accidents  teach  us  about  Nerves.  But  accidents 
are  frequent,  and  they  teach  scientists  wonderful  facts 
about  those  long  nerve  fibers.  One  of  these  facts  is  that 


224        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

nerves  are  useful  or  not,  according  as  they  remain  un- 
broken. Think  of  the  baby  who  burned  his  fingers.  His 
nerves  of  feeling  and  nerves  of  motion  were  in  good 
running  order;  he  felt  pain  and  could  pull  his  hand 
away ;  but  if  a  certain  set  of  fibers  had  been  cut  across 
so  that  the  connection  was  broken,  no  stimulus  would 
have  reached  his  brain.  The  baby  could  then  have  left 
his  fingers  in  the  fire  until  they  were  burned  off,  with- 
out feeling  the  slightest  pain.  If,  on  the  other  hand, 
a  different  set  of  fibers  had  been  cut,  no  command 
could  have  reached  the  fingers  from  the  brain.  The 
baby  would  have  suffered  frightful  pain,  but  he  would 
not  have  been  able  to  move  his  fingers  back  or  forth 
to  get  out  of  trouble.  His  arm  muscles  would  have 
had  to  come  to  the  rescue  of  finger  muscles  and  pull 
the  hand  away. 

If  both  sets  of  fibers  had  been  cut,  the  baby  would 
not  have  felt  any  pain,  nor  would  he  have  been  able 
to  move  his  fingers.  But  the  burning  would  have  gone 
on  just  the  same. 

Truthful  and  Untruthful  Messages.  The  impulse  which 
passes  over  a  fiber  is  always  truthful  if  that  fiber  is  un- 
cut and  uninjured  from  end  to  end ;  but  if  damage  has 
been  done,  strange  reports  may  reach  the  brain.  Old 
soldiers  testify  to  this.  One  of  these  men  lives  near  my 
home,  and  when  we  met  the  other  day  he  said,  "Is n't 
it  strange,  my  leg  was  cut  off  over  ten  years  ago,  but 


THE  NERVOUS  SYSTEM  225 

last  night  the  heel  of  that  foot  itched  and  pained  me 
so  that  I  thought  I  should  go  crazy?  "  "  What  did  you 
do?"  I  asked.  "Put  a  hot- water  bag  against  the  stump, 
warmed  the  thing  up,  and  finally  got  relief."  Of  course 
he  knew  as  well  as  I  did  that  something  was  irritating 
the  live  ends  of  the  fibers  that  used  to  send  reports 
from  the  heel  to  the  brain,  and  that  when  the  brain 
received  the  stimulus  it  had  no  way  of  knowing  that 
the  fibers  had  been  cut  in  two  and  that  their  extreme 
ends  were  no  lower  down  than  the  knee.  The  thinking 
and  seeing  part  of  my  friend's  brain  did  certainly  tell 
him  the  truth.  He  knew  that  there  was  no  heel  there. 
Nevertheless,  even  that  knowledge  could  not  change 
the  reports  which  faithful  fibers  were  bound  to  send  to 
headquarters  in  the  brain.  Something  was  out  of  order 
in  their  neighborhood,  and  they  clamored  for  help  until 
it  came  in  the  shape  of  a  hot-water  bag. 

Structure  of  the  Neuron.  From  all  this  it  is  evident 
that  nerves,  brain,  and  muscles  are  pretty  closely  con- 
nected. Indeed,  a  microscope  in  the  hands  of  a  scien- 
tist reveals  strange  secrets  about  this  connection  and 
about  the  structure  of  nerve  substance.  I  shall  state 
a  few  of  these  hidden  truths  in  a  straightforward,  matter- 
of-fact  way: 

i.  Just  as  muscles  are  made  up  of  muscle  fibers, 

each  one  of  which  is  a  muscle  cell,  so  too  is  nerve 

substance  made  up  of  nerve  cells. 


226        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

2.  A  nerve  cell  is  called  a  neuron.  It  is  made 
up  of  four  parts:  cell  body,  nucleus  of  the  cell, — 
its  most  essential  part,  —  axon,  dendrites.  A  nerve 
cell  has  but  one  axon.  It  stretches  off  to  a  greater 


FOUR  NEURONS 


A  and   C,  from  the  cerebellum ;   B,  from  the   spinal  cord ;  D,  from  the 

cerebrum ;  a,  the  axon.    The  cells  A  and  D  are  stained  so  that  the  main 

body  and  the  dendrites  are  black ;  B  and  C  show  the  nucleus 

distance  than  the  other  fibers.  It  is  straighter  and 
has  branches  of  its  own  that  extend  from  it  at 
right  angles.  When  a  cell  body  has  several  project- 
ing fibers  it  is  easy  to  pick  out  the  axon,  because 
the  other  fibers  —  the  dendrites  —  are  shorter  and 


THE  NERVOUS  SYSTEM 


227 


branch  out  in  crooked  and  forked  fashion.    The  cell 

body  part  of  the  neuron  is  gray,  but  the  fibers  that 

stretch  away  from  it 

look  white  because 

they  have   a  white 

covering. 

3.  Each  separate 
fiber  in  any  bundle 
of    nerve    fibers    is 
the  long  axon  arm 
of  some  neuron. 

4.  The  cell  bod- 
ies of  the    nervous 
system   are  located 
in  the  cortex  of  the 
brain,  in  the  center 
of  the   spinal   cord, 
and  in  the  ganglia. 

5.  A  ganglion  is 
a    group    of    nerve 
cells  unprotected  by 
any  bony  covering. 
There    are     impor- 
tant ganglia  in  dif- 
ferent   parts    of    the      Notice  the  countless  crooked  dendrites  and 


WHERE  THE  STIMULUS  GOES.   INTER- 
TWINED NEURONS  IN  THE  CORTEX 


body   (see    Chapter 
XVII). 


the  many  straight  axons  which  run  up  and 
down  (highly  magnified) 

(After  Kolliker) 


228       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

6.  Nerve  fibers  carry  stimuli  to  the  spinal  cord. 
There  other  fibers  from  other  cell  bodies  receive 
the  stimulus  and  hasten  it  on  to  cell  bodies  in  the 
cortex  of  the  brain.  These  cell  bodies  then  send 
down  commands  and  messages  by  other  sets  of 
connected  fibers  which  stretch  away  to  this  part 
of  the  body  or  that. 

Nerve  Telegraph  Stations.  Wherever  cell  bodies  are 
clustered,  whether  in  brain,  spinal  cord,  or  ganglion, 
there  we  have  that  interesting  place,  a  nerve  telegraph 
station.  It  resembles  a  city  telegraph  station  in  two 
ways: 

1.  It  has  fibers  that  do  the  work  of  wires  and  con- 
nect it  with  different  points  here  and  there.    These 
carry  messages  hither  and  thither. 

2.  If  a  fiber  is  separated  from  its  own  particular 
cell  in  that  central  cluster,  it  is  as  useless  as  is 
a  telegraph  wire  after  it  has  been  separated  from 
its  telegraph  station. 

We  see,  then,  that  the  vital  part  of  each  nerve  cell 
is  the  gray  cell  body,  and  we  realize  why  it  is  that  a 
cluster  of  hundreds  and  thousands  of  these  cells  becomes 
one  of  the  most  fascinating  centers  of  activity  in  the 
world.  Especially  so,  when  it  appears  that  each  fiber 
that  enters  the  central  station  is  responsible  for  one  sort 
of  message  alone,  and  that,  so  far  as  we  know,  it  can 
never  carry  a  message  of  any  other  kind. 


THE  NERVOUS   SYSTEM  229 

Since  the  two  sets  of  fibers  carrying  messages  in 
opposite  directions  are  so  close  together,  the  ignorant 
person  might  ask  whether  or  not  any  mistakes  are 
ever  made  in  the  work  they  do.  The  answer  is,  that 
this  never  happens.  Never  in  a  single  instance  does 
any  fiber  in  any  bundle  carry  a  message  the  wrong  way 
or  exchange  its  message  for  that  which  a  neighbor  fiber  is 
carrying.  The  reason  is  that  each  fiber  is  separated  from 
all  the  others  by  its  own  particular  outside  wrapping. 

What  the  Gray  and  White  Substances  are.  And  now 
we  understand  the  gray  and  white  substances  of  the 
brain.  The  gray  is  a  mass  of  millions  of  cell  bodies 
packed  together  and  joined  to  each  other  by  white- 
covered  fibers. 

The  white  stuff  is  a  compact  mass  of  fibers,  each 
one  of  which  stretches  away  in  its  silvery  sheath  from 
its  individual  cell  in  the  gray  layer.  Millions  of  these 
fibers  join  one  part  of  the  brain  to  another  part  of  the 
same  brain.  Still  other  millions  go  downward  towards 
the  spinal  cord,  and  there,  within  the  firm  protection 
of  the  backbone,  stimuli  of  every  sort  speed  upward 
to  the  brain,  while  at  the  same  instant,  on  other  fibers, 
countless  commands  go  from  the  brain  to  the  muscles 
of  the  body.  It  was  by  studying  these  commands  and 
stimuli  that  men  learned  at  last  what  special  work  is 
always  done  in  special  regions  of  the  brain.  By  the  same 
study,  also,  they  learned  what  fatigue  does  to  nerve  cells. 


230       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Fatigue  and  its  Remedy.  Several  years  ago  Dr.  C.  F. 
Hodge  studied  the  brain  of  the  English  sparrow  and 
learned  some  astonishing  facts  about  fatigue  and  rest. 
He  made  two  examinations  every  day;  one  in  the  morn- 
ing, to  see  how  the  cells  looked  after  a  long  night  of  rest, 
the  other  in  the  evening,  to  see  how  they  looked  after 

the  day's  work  was  done. 
His  great  discovery  was 
that  always  the  innermost 
center  of  each  cell  —  the 
nucleus  —  was  plump  and 
round  and  full  in  the 

A  SPARROW  WHOSE  BRAIN  CELLS  ARE     morning    before    WOrk    be- 
GROWING  WEARY  WITH  WORK  gan>  anj  fa^t  Jt  was  much 

smaller,  much  more  jagged  and  irregular,  after  the  day's 
work  was  over.  From  his  experiments  Dr.  Hodge  de- 
cided that,  for  all  of  us  who  own  brain  cells,  it  is  the 
cell  body  and  not  the  fiber  of  each  neuron  that  gets  tired. 
The  case  for  one  and  all  can  be  stated  in  two  sentences. 

1.  Before  exertion  the  nucleus  is  large  and  round, 
smooth  and  regular. 

2.  After  prolonged  exertion  the  nucleus  is  small, 
jagged,  and   irregular.     It  has   lost  substance  and 
become  crumpled. 

Dr.  Hodge  also  learned  that  when  tired  cells  have 
a  chance  to  rest,  the  nucleus  grows  larger,  rounder,  and 
more  regular  again.  From  these  and  other  experiments 


THE  NERVOUS  SYSTEM  231 

we  learn  that  when  we  are  tired  in  body  or  brain  we 
cannot  expect  satisfactory  work  from  our  nerve  cells, 
and  that  we  should  not  overtax  them  when  already  tired. 
This  does  not  mean  that  vigorous  exercise  does  us  harm. 
On  the  contrary,  it  is  absolutely  necessary  to  us.  The 
one  point  to  remember  is  that  we  must  always  balance 
exercise  by  rest.  The  man,  woman,  or  child  who  gets 
up  tired  in  the  morning  is  losing  the  balance  between 
work  and  rest.  He  is  getting  too  little  sleep  to  offset 
his  fatigue.  If  he  wishes  to  do  good  work,  he  must  rise 
in  the  morning  with  the  feeling  of  being  rested.  By  this 
feeling  he  will  know  that  his  nerve  cells  are  in  prime 
condition,  ready  to  serve  him  well. 

QUESTIONS 

1.  Mention  ways  in  which  sensations  help  us.  2.  What  does  the 
microscope  show  about  the  nerves  ?  3.  Describe  the  work  of  different 
sets  of  fibers  when  a  baby  sees  a  flame  and  puts  his  finger  into  it. 
4.  What  does  the  brain  do  when  the  stimuli  reach  it?  5.  Which  are 
the  longest  fibers  ?  6.  Describe  the  distribution  of  the  nerves.  7.  Where 
do  we  find  great  clusters  of  nerves  ? 

8.  Describe  the  dog  that  had  lost  the  use  of  the  cerebrum.  9.  What 
of  man  when  he  loses  his  cerebrum  ?  10.  What  mental  activities  are 
connected  with  the  cerebrum?  11.  Where  is  the  cerebrum  located? 
12.  Describe  the  appearance  of  a  brain  preserved  in  alcohol.  13.  Where 
are  the  parts  held  together  ?  14.  Give  the  names  of  two  important  divi- 
sions of  the  brain.  15.  Name  the  larger  and  describe  it.  16.  Where  is 
the  cerebellum  ?  17.  What  can  you  say  about  brain  convolutions  ?  about 
the  thickness  of  the  gray  layer  ?  about  its  use?  18.  What  about  injury  to 


232        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

special  parts  of  it  ?  19.  Describe  the  centers  in  the  cerebrum.  20.  What 
is  the  cortex?  21.  Tell  how  important  it  is,  and  how  it  is  protected. 
22.  What  separates  the  brain  from  the  skull? 

23.  What  is  the  difference  between  large  nerves  and  small  nerves? 
24.  Where  are  the  largest  nerves  found?  25.  Describe  the  backbone 
and  the  nerves  that  pass  through  it.  26.  How  many  fibers  may  be  in 
each  nerve?  27.  How  do  fibers  pass  from  one  bundle  to  another? 
28.  Is  there  danger  of  their  losing  their  way  ?  29.  What  points  do 
fibers  connect?  30.  When  do  fibers  become  useless?  31.  What  would 
have  happened  to  the  baby  who  burned  its  fingers  if  certain  sets  of  nerve 
fiber  had  been  cut  across?  32.  Let  six  pupils  give  six  facts  about  the 
neuron.  33.  In  what  two  ways  is  a  cluster  of  cell  bodies  —  a  ganglion 
—  like  a  telegraph  station?  34.  What  is  the  essential  part  of  a  nerve 
cell?  35.  How  often  do  fibers  make  mistakes?  36.  How  often  do 
they  exchange  messages  ?  37.  What  is  the  gray  layer  of  the  brain  ?  the 
white  part  of  the  brain  ?  38.  Describe  a  tired  nerve  cell.  39.  What 
is  the  point  to  remember  about  fatigue  and  rest? 


CHAPTER  XVI 

TRAINING  THE  CEREBELLUM  AND  THE  SENSES 

The  Work  of  the  Cerebellum.  A  French  scientist  named 
Flourens  once  noticed  that  although  a  pigeon  with  a 
useless  cerebellum  does  not  seem  to  suffer,  it  does,  never- 
theless, have  the  greatest  difficulty  in  standing  and  in 
moving  about.  He  saw  that  when  it  moves,  the  muscles 
do  not  pull  together  in  orderly  fashion,  but  rather  in  an 
independent,  helter-skelter  way, — each  muscle,  as  it  were, 
pulling  for  itself  without  reference  to  any  other  muscle, 
so  that  instead  of  walking,  the  poor  bird  turns  one 
somersault  after  another  in  rapid  succession. 

Dr.  Flourens  -also  noticed  that  the  less  the  cerebellum 
is  injured,  the  less  the  pigeon  is  troubled  with  these  dis- 
orderly movements,  although  even  then  it  walks  in  a 
staggering,  drunken  way. 

From  these  and  other  facts  which  they  have  gathered, 
men  who  study  the  subject  conclude  that  the  cerebellum 
is  an  enormous  help  to  the  cerebrum  in  the  matter  of 
controlling  such  muscles  as  are  guided  by  our  will  power. 
They  say  that  while  the  cerebrum  is  the  commanding 
general  of  the  nervous  system,  the  cerebellum  is  the 

233 


A—- 


234        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

chief  of  staff,  the  one  that  helps  take  charge  of  num- 
berless movements  which  we  have  learned  to  make 
through  persistent,  diligent  practice.  When  we  were 
babies  and  were  learning  to  walk,  we  thought  about  each 
step  as  we  took  it.  If  our  minds  were  diverted,  if  certain 

special  neurons 
stopped  attending 
to  our  footsteps,  we 
tumbled  down  in- 
stantly. For  weeks, 
and  even  months, 
we  hardly  dared  to 
walk  alone. 

To-day,  however, 
after  years  of  prac- 
tice, we  walk 
anywhere  without 
giving  a  thought 
to  any  separate 
footstep.  We  even 
step  so  fast  that 
we  run  and  dance ;  we  ride  the  bicycle,  and  we  swim. 
Indeed  we  do  all  this  so  well,  and  we  are  able  to  think 
of  so  many  other  things  while  we  use  our  feet  and  hands, 
that  it  looks  very  much  as  if  they  had  become  quite  in- 
dependent of  the  brain.  This,  in  fact,  explains  the  whole 
situation.  Their  movements  have  at  last  been  put  in 


CELLS  IN  THE  CEREBELLUM 

They  guide  our  unconscious  movements.    A,  D,  £, 
cell  bodies ;  B,  C,  fibers 

(After  Ramon  y  Cajal) 


TRAINING  THE  CEREBELLUM  AND  THE  SENSES      235 

charge  of  a  different  set  of  nerve  cells.  The  happy  part 
of  this  arrangement  is  that  the  particular  neurons  which 
do  what  we  might  call  this  underground  managing  for  us 
are,  as  a  rule,  more  trustworthy  than  those  which  help 
our  conscious  thinking  and  moving. 

Training  the  Neurons.  The  same  law  and  the  same 
power  of  the  neurons  hold  good  in  other  directions  also. 
What  trained  baseball  player  stops  to  think  of  each  sepa- 
rate run  and  slide,  how  to  hold  the  bat,  how  to  pitch  the 
curved  ball,  how  to  catch  it?  He  simply  takes  his  place 
to  play  the  game ;  he  trusts  his  trained  neurons  to  help 
him,  and  he  finds  that  almost  unconsciously  he  makes 
the  right  motion  at  the  right  instant,  that  he  plays 
the  game  even  better  than  he  could  tell  another  how  to 
play  it. 

This  is  quite  as  true  in  still  other  kinds  of  action.  I 
know  a  freshman  in  college  who  has  lately  taken  up  a 
noticeable  practice.  Often  when  he  stands  still,  and 
even  while  he  walks,  he  may  be  seen  suddenly  to 
straighten  his  neck  and  press  the  back  of  it  firmly 
against  the  inside  of  his  collar.  Why  does  he  do  it? 
Simply  because  he  believes  that  his  head  bends  too 
far  forward  to  be  creditable,  and  he  has  made  up  his 
mind  to  put  his  neck  muscles  in  charge  of  a  new  set 
of  neurons.  Whenever  he  thinks  about  it,  therefore, 
he  sends  imperative  orders  to  those  muscles.  They 
straighten  his  neck  promptly,  and  he  gets  his  head  up 


236        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

where  it  belongs.  He  knows  that  each  pull  in  the  right 
direction  helps,  and  that  if  he  persists  long  enough  he 
will  finally  get  his  neurons  so  well  trained  that  they  will 
end  by  making  the  muscles  hold  his  head  up  all  the 
time  without  any  conscious  thought  about  it  on  his 
own  part,  and  that  this  will  relieve  his  mind  for  other 
affairs. 

Results  of  Training  the  Neurons.  When  we  are  teach- 
ing ourselves  new  lessons,  the  time  for  encouragement 
is  at  the  first  sign  that  we  are  doing  the  desired  thing 
unconsciously.  For  example,  we  may  be  training  various 
sets  of  nerve  cells  to  help  us  do  certain  things  in  defi- 
nite ways,  —  to  walk  like  a  soldier,  to  sit  erect,  to  talk 
in  a  low  voice,  to  hold  knife  and  fork  and  spoon  as  we 
should,  to  recite  the  multiplication  table,  or  to  repeat 
a  poem,  —  and  day  after  day  we  may  be  discouraged 
by  the  fact  that  as  soon  as  our  own  thought  is  off  the 
subject  we  fail  in  our  struggle ;  but,  without  warning, 
some  day  the  moment  for  encouragement  will  come. 
We  shall  find  that  we  have  done  the  desired  thing  as 
we  wished  to  do  it,  even  while  we  were  not  thinking 
about  it,  and  by  that  sign  we  shall  know  that  we  have 
reached  the  turning  point.  By  being  persistent  a  little 
longer,  those  particular  neurons  will  have  their  lesson 
by  heart,  the  fight  will  be  won. 

This  method  of  training  is  admirable  for  any  neurons 
which  we  wish  to  press  into  service,  but,  even  when  we 


TRAINING  THE  CEREBELLUM  AND  THE  SENSES      237 

are  not  training  them  on  purpose,  they  often  get  trained 
in  spite  of  our  real  desire.  As  an  example,  think  of  those 
which  control  the  muscles  of  the  face.  When  you  are 
glad  or  sad  some  day,  try  to  catch  the  expression  of 
your  face  in  the  mirror,  or  look  at  the  face  of  some 
one  else  who  is  happy,  or  angry,  or  suffering  great  pain. 
In  every  such  case  you  will  find  that,  unconsciously,  the 
muscles  tell  a  plain,  straightforward  story. 

Neurons  and  Facial  Expression.  The  truth  of  course 
is  that  almost  every  feeling  we  have  may  express  itself 
in  the  face,  and  that  each  repetition  of  the  expression  is 
one  more  lesson  for  the  nerve  cells  that  control  those 
muscles  to  learn.  The  sad  man,  the  worried  man,  the 
happy  man,  the  hopeful  or  the  discouraged  man  —  each 
has  his  own  telltale  face  muscles,  and  a  good  student  of 
human  nature  learns  to  read  these  faces  almost  as  easily 
as  if  they  were  the  pages  of  a  book  spread  out  before 
him.  It  is  evident,  then,  that  every  young  face  is  shap- 
ing itself  to  the  expression  it  will  have  later,  and  that 
the  time  is  sure  to  come  when  the  tale  of  our  inner 
lives  will  be  told  by  the  outward  expression  of  face  and 
manner.  When  this  time  arrives  we  may  long  to  hide 
the  facts  about  the  history  of  our  emotions.  But  we 
shall  find  that  we  cannot  cheat  the  neurons.  Instead, 
the  story  which  they  'have  been  trained  to  tell  will 
proclaim  the  facts  about  us  whenever  and  wherever 
we  show  ourselves. 


238        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Four  Great  Truths  about  Neurons.  Thus  far  in  this 
chapter  we  have  laid  bare  four  great  facts: 

1.  He  who  wishes    to   learn  to  do  any  sort  of 
muscular  work  easily  and  well,  and  to  make  sure 
that  what  he  has  learned  cannot  be  forgotten,  must 
by  diligent  practice  put   the  performance  of  that 
special  work  in  charge  of  its  own  set  of  unconscious 
neurons. 

2.  Neurons  are  often  so  quick  and  clever  that 
they  learn  that  which  we  would  much  rather  they 
would  not  learn,  and  they  proclaim  the  truth  even 
when  we  wish  them  to  hide  it. 

3.  If  we  wish  our  neurons  to   declare   that  we 
are  courageous,  kind,  and  sincere,  the  only  way  to 
make  them  do  it  is  by  being  courageous,  kind,  and 
sincere. 

4.  He  who  pretends  to  have  desirable  qualities 
when  he  really  lacks  them  will  find  that  through 
the  power  of  his  neurons,  in  spite  of  his  desire, 
he    actually    declares    to    those    whom    he    meets 
that  it  is  all  mere  pretense. 

In  addition  to  all  else,  our  special-sense  neurons 
need  training.  They  are  located  in  the  cortex,  and 
they  control  seeing,  hearing,  touch,  taste,  and  smell. 

Training  the  Senses.  A  friend  of  mine  whose  senses 
are  all  in  good  working  order  is  developing  two  of 
them  in  a  delightful  way.  He  thinks  he  is  simply 


TRAINING  THE  CEREBELLUM  AND  THE  SENSES      239 

studying  birds.  This  indeed  he  does,  but  while  he 
studies  birds  his  eyesight  grows  keener  in  its  power 
to  recognize  them,  while  his  hearing  also  grows  more 
trustworthy;  and  the  outcome  of  it  is  that  almost 
never  does  a  bird  fly  overhead  within  sight  or  sound 
of  him  but  he  recognizes  it  at  once. 

Sometimes  he  knows  it  by  the  way  it  flies;  some- 
times by  the  color  of  wing,  breast,  or  tail ;  sometimes 
by  its  shape ;  sometimes  by  its  size ;  sometimes  by 
its  song.  Whatever  the  mark,  in  a  flash,  when  he 
sees  the  bird  or  hears  it,  he  knows  it  and  names  it. 
Others  who  are  with  him  may  have  seen  nothing  but 
a  bit  of  color  passing  by  or  a  small  shape  on  a  sway- 
ing tree  top ;  but  he  has  seen  and  heard  all  that  the 
trained  eye  and  ear  can  see  and  hear,  and  he  is  able 
to  give  to  the  color,  the  shape,  or  the  sound  its  own 
definite  bird  name. 

Whether  a  man  watches  birds  or  collects  stamps, 
coins,  or  pictures,  —  whether  he  isr  blacksmith,  preacher, 
carpenter,  lawyer,  merchant,  editor,  sailor,  or  newsboy, 
—  he  will  find  that  trained  senses  lead  to  the  promised 
land  of  success. 

Men  in  all  countries  have  discovered  this  for  them- 
selves. We  are  told l  that  natives  in  central  Australia 
know  every  bird  track  and  every  beast  track  by  sight, 
and  that  this  knowledge  does  not  come  to  them 

1  Related  by  Baldwin  Spencer  and  F.  C.  Gillen. 


240       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

through  any  accident.  It  seems,  indeed,  that  from 
earliest  childhood  Australian  boys  and  girls  are  taught 
to  notice  tracks  of  all  sorts,  and  that  at  the  same 
time  they  are  also  taught  to  imitate  these  tracks  with 
their  fingers  in  the  sand. 

The  result  is  that  a  full-grown,  experienced  tracker, 
as  he  is  called,  can  follow  obscure  tracks  which  we 
should  never  notice  and  can  recognize  them  even  as 
he  rides  past  rather  swiftly  on  the  back  of  a  horse. 

But  eyesight  and  touch  do  not  stand  alone ;  the  power 
to  smell  may  be  trained,  too.  Think  of  the  Indians  in 
Peru.  Dr.  Carpenter  says  that  in  the  darkest  night 
these  people  can  tell,  by  the  smell  which  reaches  them, 
whether  a  stranger  who  approaches  is  an  Indian,  a 
European,  or  a  negro.  For  them,  as  for  the  others,  it 
is  a  trained  sense  that  does  the  work. 

We  see,  then,  that  the  same  law  is  true  for  all  sorts 
of  people,  in  lands  however  far  apart.  Everywhere,  he 
who  wishes  the  keenest  and  the  surest  sense  of  sight  or 
sound,  taste  or  smell  or  touch,  may  secure  it  by  close 
attention  and  constant  practice.  In  other  words,  by  atten- 
tion and  diligent  practice  we  may  form  right  habits  for 
our  senses  and  develop  the  power  which  we  desire. 

The  encouragement  is  that  by  being  persistent  enough 
in  the  direction  of  the  senses  —  or  in  any  other  direction 
—  we  compel  the  nervous  system  to  help  us  form  habits 
that  will  stand  by  us  for  life. 


O 

w 


241 


242        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Machinery  of  the  Senses.  Along  with  all  these  facts 
it  is  important  to  remember  that  each  separate  sense 
depends  on  the  work  done  by  three  parts  of  a  delicate 
piece  of  machinery. 

1.  Apparatus  in  which  nerve  endings  receive  the 
stimulus  —  eye,  ear,  nose,  skin,  etc. 

2.  Fibers  which  carry  the  stimulus. 

3.  Cell  bodies  in  the  cortex  —  the  gray  covering 
of  the  brain  —  which  recognize  the  stimulus. 

The  Brain  the  Center  of  the  Senses.  In  the  case  of 
each  sense,  also,  we  must  suppose  that  the  outside  ap- 
paratus itself  knows  no  more  about  what  is  happening 
to  it  than  the  mouthpiece  of  a  telephone  knows  what 
we  say  when  we  speak  into  it.  In  point  of  fact  the  re- 
ceiving apparatus  of  each  sense  is  nothing  more  than  a 
marvelous  device  for  receiving  its  own  special  kind  of 
stimulus.  Eye,  ear,  skin,  nose,  tongue  —  each  is  a  piece 
of  apparatus  fitted  with  nerve-endings  that  receive  stim- 
uli of  a  certain  kind  and  send  them  to  the  brain  on  a 
distinct  set  of  fibers.  The  cell  bodies  in  the  brain  feel 
our  sensations  for  us. 

Since  we  know  that  exercise  develops  any  part  of  the 
body,  and  since  we  have  learned  that  our  senses  may  be 
developed  by  habits  of  attention  and  by  constant  prac- 
tice, we  are  not  surprised  to  hear  that  by  examining  a 
brain  after  death  a  trained  scientist  can  tell  just  which 
set  of  nerve  cells  did  the  most  work  during  life. 


TRAINING  THE  CEREBELLUM  AND  THE  SENSES      243 

Enlargement  of  Sense  Centers.  These  men  may,  for 
example,  take  a  bird  that  has  lost  its  life  and  point  to 
a  certain  place  on  the  cortex.  "  You  see  it  is  very  much 
enlarged,"  they  say.  *  That  is  the  part  that  always  had 
the  most  exercise.  It  is  the  sight  center  of  the  brain." 
And  at  once  we  call  to  mind  the  stories  we  have  heard 
about  carrier  pigeons  —  about  the  keenness  of  their 
vision  and  the  distance  they  fly  to  reach  home  again. 

The  brain  of  a  dog  may  be  examined  next.  "  There !  " 
the  scientist  exclaims,  "do  you  see  this  part?  It  is  the 
center  for  smell,  and  it  is  always  greatly  enlarged  in 
dogs."  And  now  we  recall  all  our  dog  stories.  We  re- 
member that  a  bloodhound  will  trace  a  man  through  a 
crowded  city,  that  the  scent  of  a  dog  is  one  of  his  most 
remarkable  points. 

The  examination  might  go  on  from  animal  to  animal, 
each  brain  showing  that  one  of  the  senses  was  more 
highly  developed  than  the  others. 

The  Sense  Centers  of  Laura  Bridgman.  Human  brains 
are  better  balanced,  unless  something  has  gone  wrong. 
This  was  true  of  Laura  Bridgman.  She  was  deaf  and 
dumb  and  blind  and  had  no  sense  of  smell.  Her  one 
connection  with  the  world  was  through  her  sense  of 
touch.  As  a  result,  the  cell  bodies  of  touch  received 
constant  daily  exercise,  while  the  nerve  cells  of  all  the 
other  senses  received  no  exercise  whatever.  Then  came 
the  startling  discovery;  for  after  Laura  Bridgman  died 


244       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

her  brain  itself  told  the  story  of  her  senses.  Doctors 
examined  the  cortex  and  found  that  it  was  thinnest 
at  the  centers  of  seeing,  hearing,  tasting,  and  smelling. 
More  than  this,  as  might  have  been  expected,  the  doc- 
tors also  found  that  the  touch  region  of  Laura's  brain 
was  wonderfully  developed.  In  view  of  all  this  we  draw 
the  following  conclusions  for  immediate  use : 

1.  Although  the   apparatus   itself   does    nothing 
but  receive  stimuli  of  one  sort  or  another,  still,  if 
it  is  ruined  by  disease,  accident,  or  careless  use,  no 
amount  of  striving  on  our  part  will  restore  it  to  us. 

2.  If  the  apparatus  of  one  sense  has  been  wrecked, 
the  other  senses  may  be  so  highly  developed  as  to 
help  make  up  the  loss. 

3.  Persistent  exercise  of  any  sense  will  increase 
the  thickness  of  the  part  of  the  cortex  to  which  it 
belongs. 

Although  no  examination  of  the  cortex  of  our  own 
cerebrum  is  possible  while  we  are  alive,  still  we  may 
have  the  comfort  of  knowing  that  we  are  improving  its 
quality  here  or  there  in  proportion  as  we  are  giving  one 
sense  or  another  more  or  less  exercise.  The  truth  is  that 
our  senses  are  our  best  friends  or  our  worst  enemies  in 
just  such  measure  as  we  train  or  neglect  them. 

By  the  foregoing  facts  we  have  learned  that  five 
special  senses  are  the  avenues  that  lead  up  to  the 
mind.  -The  following  additional  facts  are  valuable. 


TRAINING  THE  CEREBELLUM  AND  THE  SENSES      245 

Structure  of  the  Eye.  Here  we  have  a  socket  of  bone 
lined  with  a  cushion  of  fat.  Within  this  socket  is  the 
eyeball.  To  protect  it  are  eyelid,  eyelashes,  and  the 
eyebrow.  Six  small  muscles  move  the  eyeball  about. 
One  end  of  each  is  fastened  to  the  eyeball,  the  other 
end  to  the  inside  of  the  socket  itself.  The  lachrymal 


ch 


THE  WAY  THE  IMAGE  OF  AN  OBJECT  REACHES  THE  RETINA 

i,  2,  the  object;  i',  2',  image  of  the  same;  <:,  cornea;  /,  iris;  /,  lens;  v,  vitreous 
humor;  w,  sclerotic;  ch,  choroid;  o.n.,  optic  nerve 

gland,  within  the  socket,  manufactures  moisture  con- 
stantly. This  moistens  the  eyeball,  then  runs  off  through 
two  small  canals,  one  from  the  inside  corner  of  each  eye- 
lid. From  these  canals  tears  run  into  the  nasal  duct  and 
then  into  the  nose.  If  the  lachrymal  glands  manufacture 
moisture  very  fast,  the  eyes  overflow,  tears  stream  down 
the  cheeks,  and  we  say  the  person  is  crying.  We  mean 
that  the  duct  cannot  carry  the  liquid  off  fast  enough. 


246        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

The  eyeball  is  made  up  of  three  layers :  the  sclerotic 
coat  outside,  the  choroid  coat,  and  the  retina  inside. 
The  sclerotic  coat  is  really  the  white  of  the  eye.  In 
front  it  is  joined  to  the  cornea.  This  is  transparent,  like 
a  window,  and  through  it  light  goes  into  the  eye.  Back 
of  the  cornea  lies  the  iris,  a  circular  curtain  of  muscle, 
lined  with  coloring  matter  and  pierced  by  a  round  open- 
ing called  the  pupil,  through  which  light  enters.  The 
size  of  this  opening  is  controlled  by  muscles  which  make 
it  smaller  in  bright  light  and  larger  in  dim  light.  This 
iris  curtain  is  the  colored  part  of  the  eye.  What  is  the 
color  of  your  iris?  The  crystalline  lens  is  back  of  the 
iris.  It  focuses  the  light  on  the  retina.  It  also  divides 
the  inside  of  the  eyeball  into  two  compartments.  The 
small  one  in  front,  just  behind  the  cornea  and  divided 
in  two  by  the  iris,  is  filled  with  a  watery  substance,  the 
aqueous  humor,  that  runs  out  if  the  eyeball  is  cut  into. 
The  large  compartment  back  of  the  lens  is  filled  by  a 
transparent  jellylike  substance  inclosed  in  a  membrane 
and  called  the  vitreous  humor.  Behind  all  this  is  the 
lining  of  the  back  of  the  eye  —  the  retina. 

The  optic  nerve  enters  the  eye  from  the  cerebrum  and 
spreads  itself  out  on  the  retina.  Light  rays  enter  through 
the  pupil  in  the  cornea,  pass  through  the  crystalline  lens, 
strike  on  the  retina,  and  make  an  image  there.  By  the 
help  of  the  optic  nerve  the  seeing  center  of  the  brain 
receives  the  picture  in  a  flash.  The  whole  structure  is 


TRAINING  THE  CEREBELLUM  AND  THE  SENSES      247 

a  marvelous  camera,  more  delicate  than  any  man-made 
device.  We  need  to  treat  it  with  the  greatest  care.  The 
following  directions  are  important : 

Treatment  of  Eyes;  Headache,  Eyestrain,  etc.  In  strong 
light,  lower  the  eyelids.  Sit  erect  while  reading.  Have  a 
good  light  on  any  close  eye  work  —  reading,  embroidery, 
drawing,  and  the  like.  Light  should  shine  upon  the 
work  from  the  left.  It  should  not  shine  into  the  eyes. 
Avoid  twilight  reading.  Do  most  of  your  eye  work  by 
daylight,  not  by  artificial  light.  Eyes  are  strained  by 
light  that  flickers  or  is  dim.  Any  strain  damages  the 
eyesight.  Hold  your  book  about  eighteen  inches  from 
the  eyes.  If  you  cannot  do  this  without  eyestrain,  if  you 
have  frequent  headache  and  no  auto-intoxication,  your 
eyes  should  be  examined.  You  may  be  nearsighted, 
and  have  to  hold  your  work  too  near  to  the  eyes.  You 
may  be  farsighted  or  even  slightly  cross-eyed.  You  may 
have  what  is  known  as  astigmatism.  In  any  case  of 
strain,  see  the  oculist.  He  will  give  you  glasses  that  will 
correct  the  trouble.  Spectacles  are  always  better  than 
eyeglasses,  because  they  are  steadier  on  the  nose.  They 
strain  the  eyes  less.  Whether  you  wear  glasses  or  not, 
in  any  close  eye  work  look  up  frequently  to  rest  the  eyes. 
Remember  that  you  have  but  one  pair  to  serve  you 
through  life,  and  that  the  better  you  treat  them  the 
longer  they  will  last.  Use  your  eyes  very  carefully  after 
measles,  scarlet  fever,  chicken  pox,  diphtheria,  and  any 


248        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

disease  that  weakens  the  system.  Never  wipe  the  eyes 
on  a  public  towel.  Disease  microbes  may  be  on  it.  Keep 
your  own  ringers  from  your  eyes  for  the  same  reason. 

Structure  of  the  Ear.    The  outer  ear  includes  all  we 
see  of  it,  and  also  the  auditory  canal  into  which  sound 


A    CUT  THROUGH   THE   RIGHT   EAR 

a,  the  tube ;  d,  the  eardrum ;  c,  the  ear  bones ;  d,  the  snail  shell ;  <?,  the  nerve 

of   hearing 

waves  go.  At  the  inside  end  of  this  canal  is  the  mem- 
brane called  the  eardrum.  It  is  stretched  across  the 
canal,  and  sound  waves  that  strike  against  it  make  it 
vibrate.'  A  blow  on  the  ear  often  breaks  it.  On  the 


TRAINING  THE  CEREBELLUM  AND  THE  SENSES      249 

sides  of  the  canal  are  small  glands  which  secrete  wax, 
a  protection  to  the  drum.  The  middle  ear  is  just  be- 
yond the  drum.  In  it  are  three  tiny  bones,  called  ham- 
mer, anvil,  and  stirrup.  Ligaments  of  the  smallest  size 
hold  the  bones  together  in  a  chain  and  fasten  them  to 
the  underside  of  the  drum.  When  sound  waves  reach 
the  drum  it  vibrates.  The  small  bones  are  slightly 
moved  by  this  vibration  and  pass  it  on  to  the  cochlea 
at  the  entrance  of  the  inner  ear.  This  cochlea  is  an 
intricate  structure  shaped  like  a  shell.  Within  the  inner 
ear  are  bony  spaces  and  tubes,  called  the  bony  laby- 
rinth. Inside  the  bony  labyrinth  is  the  membranous 
labyrinth.  And  here  it  is  that  we  find  the  ends  of  the 
fibers  of  the  nerve  of  hearing  —  the  auditory  nerve. 

These  nerve  endings  receive  vibrations  of  sound. 
The  vibrations  travel  to  the  brain  on  the  auditory  nerve. 
It  is  in  the  brain  that  we  do  our  hearing.  The  en- 
tire ear  with  its  three  parts  —  outer,  middle,  and  inner 
—  is  merely  a  combination  that  forms  the  road  by 
which  sound  waves  must  travel  to  reach  the  special 
hearing  center  of  the  brain.  The  eustachian  tube  is  a 
narrow  connecting  passage  between  the  middle  ear 
and  the  pharynx. 

Hygiene  of  the  Ear.  Three  things  must  be  done  for 
the  health  of  the  ear: 

i.  Keep  the  auditory  canal  clean,  that  wax  may 
not  accumulate  in  it. 


250       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

2.  Don't   catch   cold.     This    often    inflames   the 
eustachian  tube  and  other  membranes,  giving  in- 
tense earaches. 

3.  Never  box  the  ear.    The  sudden  crowding  of 
air  against  the  eardrum  may  split  it. 

The  Sense  of  Smell.  Smell  stimuli  are  received  by 
olfactory  cells  spread  out  on  the  sensitive  lining  of  the 
nose.  Nerve  fibers  go  from  these  cells  up  to  the  brain, 
and  there  it  is,  in  one  definite  locality,  that  we  do 
our  smelling.  The  olfactory  nerve  is  simply  the  road 
thither. 

The  Sense  of  Taste.  Nerve  endings  on  the  tongue  are 
called  "  buds  of  taste."  Each  is  joined  to  the  brain  by 
many  nerve  fibers,  and  these  transmit  taste  stimuli  to 
the  brain.  It  is  in  the  taste  center  of  the  brain  that 
we  do  our  tasting. 

The  Sense  of  Touch.  By  means  of  this  fifth  sense, 
endless  information  reaches  the  brain  from  the  surface 
of  the  body.  The  nerve  endings  themselves  are  in  the 
skin.  Longer  and  shorter  nerve  fibers  carry  touch  mes- 
sages to  the  brain,  and  there  we  do  our  feeling. 

QUESTIONS 

1.  Describe  Flourens'  work  with  pigeons.  2.  How  does  the  cere- 
bellum relieve  the  cerebrum  ?  3.  Describe  learning  to  walk.  4.  Men- 
tion other  activities  that  end  by  being  done  unconsciously.  5.  Describe 
training  the  neurons.  6.  What  are  the  results?  7.  What  causes  a 


TRAINING  THE  CEREBELLUM  AND  THE  SENSES      251 

person's  facial  expression  ?  8.  Describe  some  case  in  which  nerve 
cells  are  trained  in  spite  of  our  real  desire.  9.  Give  the  four  great 
laws  of  nerve  cells.  10.  In  studying  birds,  what  special  senses 
are  trained?  11.  How  do  native  Australians  train  their  eyesight? 
12.  In  training  the  senses,  what  is  the  secret  of  success?  13.  What 
three  parts  are  there  to  the  machinery  of  each  separate  sense? 
14.  Where  is  the  center  of  the  senses?  15.  What  can  you  say  about 
the  enlargement  of  sense  centers  ?  16.  Which  sense  is  most  developed 
in  a  bird?  in  a  dog?  17.  Tell  about  Laura  Bridgman,  and  about  her 
brain  after  death.  18.  What  three  lessons  do  we  learn  from  studying 
the  senses  ?  19.  How  many  special  senses  have  we  ? 

20.  Describe  the  location  of  the  eyeball ;  its  protections  ;  the  muscles 
that  move  it.  21.  What  does  crying  show  about  lachrymal  glands? 
22.  Name  the  layers  of  the  eyeball.  23.  Why  is  the  cornea  like  a 
window  ?  24.  Where  and  what  is  the  iris  ?  the  pupil  ?  25.  What  makes 
the  pupil  grow  larger  or  smaller?  26.  Where  is  the  crystalline  lens? 
27.  What  does  it  do?  28.  What  is  the  aqueous  humor?  the  vitreous 
humor?  29.  Where  does  the  optic  nerve  spread  out?  30.  Mention 
different  parts  of  the  eye  through  which  light  passes  to  get  to  the 
retina.  31.  Where  is  the  picture  formed  which  we  see?  32.  Where 
do  we  really  do  our  seeing  ? 

33.  What  is  the  outer  ear?  34.  Where  is  the  eardrum?  35.  What 
makes  it  vibrate?  36.  Where  does  earwax  come  from?  37.  Describe 
the  middle  ear  and  its  bones.  38.  How  do  sound  waves  reach  the 
cochlea  ?  39.  Describe  the  cochlea ;  the  bony  labyrinth ;  the  mem- 
branous labyrinth.  40.  What  is  the  auditory  nerve  ?  41.  Where  do 
we  do  our  hearing  ?  42.  What  is  the  one  thing  that  the  entire  ear 
is  made  for? 

43.  Name  the  nerve  by  means  of  which  we  do  our  Smelling. 
44.  Where  do  we  really  smell,  in  the  nose  or  in  the  brain  ?  45.  Where 
are  the  "buds  of  taste"?  46.  What  joins  them  to  the  brain ?  47.  Where 
do  we  do  our  tasting?  48.  Where  are  the  endings  of  the  nerves  of 
touch  ?  49.  Where  is  it  that  we  do  our  feeling  of  every  kind  ? 


CHAPTER  XVII 

HAPPINESS,  HEALTH,  AND  THE  SYMPATHETIC 

GANGLIA 

Vital  Activities  Independent  of  our  Will.  Before  study- 
ing this  chapter,  test  yourself  in  two  ways:  First,  try 
with  all  your  might  to  make  your  heart  stop  beating. 
Try  to  prevent  the  great  arteries  from  expanding  and 
contracting  as  the  blood  surges  through  them  in  pulses. 
See  whether,  by  thinking  and  willing  hard  enough,  you 
can  prevent  your  sweat  glands  and  oil  glands  from 
manufacturing  salt  water  and  oil.  Will  your  stomach 
obey  you  when  you  command  it  to  stop  digesting  your 
food? 

Now  turn  the  tables.  Say  to  your  heart  as  it  pounds 
steadily  along :  "  Beat  faster.  Beat  faster.  You  must  beat 
faster."  Will  it  obey  you  ?  No ;  it  goes  neither  faster 
nor  slower  by  the  fraction  of  a  second.  Your  brain  and 
your  heart  seem  to  be  as  independent  of  each  other 
as  if  they  belonged  to  different  bodies  and  lived  in 
different  worlds. 

Nevertheless,  as  we  all  know,  life  itself  depends  on 
the  beating  of  the  heart.  We  know  that  whenever  it 

stops  and  fails  to  start  again  we  shall  die,  but  from 

252 


HAPPINESS,  HEALTH,  AND  THE  GANGLIA        253 

year's  end  to  year's  end  we  think  nothing 
about  it.  At  night  we  lie  down  to  sleep 
with  no  anxiety  lest  the  steady  pulsing 
may  cease.  By  day  we  run,  dance,  dive, 
swim,  play  leapfrog  and  football,  walk  on 
our  hands  and  turn  somersaults,  knowing 
all  the  while  that  the  heart  is  affected 
by  every  move  we  make ;  but  at  the 
same  time  we  seem  to  know  that  some- 
how the  body  has  an  arrangement  for  con- 
trolling its  most  important  machinery 
whether  we  pay  attention  to  it  or  not. 

Vital  Activities  Controlled  by  the  Gan- 
glia. Up  and  down  on  each  side  of  the 
backbone  is  a  chain  of  ganglia  which 
is  more  important  to  life,  perhaps,  than 
any  other  part  of  the  nervous  system.  It 
seems  to  be  nature's  device  for  relieving 
the  brain ;  a  device  for  keeping  the  vital 
machinery  running  by  day  and  by  night 
without  our  needing  to  think  about  it. 

This  system  of  nerves  is  the  means  by 
which  the  heart,  stomach,  and  other  organs 

which  are  independent  of  our  conscious     Sp,INAL  CoRD  WITH 

J  SPINAL  NERVES 

control  are  able  to  do  their  faithful  work     On  the  left  are  a  few 
whatever  commands  we  give  them.    It  is     sympathetic  ganglia 

/7    i      j  j  joined  by  their  rope 

cauea  the  sympathetic  nervous  system.  Of  nerve  fibers 


254        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Structure  of  the  Sympathetic  Nervous  System.  So 
far  as  location  and  arrangement  are  concerned,  it  is 
not  very  difficult  to  understand  the  facts  about  this 
system,  and  the  following  outline  will  give  them  as 
simply  as  possible : 

1.  Forty-nine   ganglia    unite   to   form    the   main 
part   of    the   sympathetic    nervous    system.     These 
ganglia  belong  together  as  a  complete  set.   Twenty- 
four  lie  on  one  side  of  the  backbone,  twenty-four 
on  the  other   side,  and   one   lies   in   front  of   the 
lowest  vertebra. 

2.  Each  of   the  forty-nine  ganglia  is  connected 
with  its   neighbor   above  and    its    neighbor   below 
by  what  might  be  called  a  rope  of  fibers. 

3.  This  string  of   ganglia,  held  together  by  its 
peculiar  fiber  rope,  seems  to  hang  like  a  loop,  with 
the  backbone  as  a  pole  in  its  center. 

4.  The  cell  bodies  in  the  different  ganglia  send 
fibers  off  to  definite  parts  of  the  body  —  to  heart, 
stomach,  liver,  and  elsewhere.     At  these  different 
places    the    fibers    are   so   closely   woven    together 
that  they  form  a  network  called  a  plexus;    small 
ganglia  are  interlaced  with  each  plexus. 

5.  One  very  important  plexus  is  near  the  heart ; 
another  is  near  the  stomach. 

A  Nerve  Plexus.  On  the  street  the  other  day  my 
six-year-old  friend  suddenly  bent  his  head  forward 


HAPPINESS,  HEALTH,  AND  THE  GANGLIA        255 

and  thumped  it  into  the  stomach  of  an  elderly  man 
who  came  that  way.  The  boy  was  surprised  when 
the  old  man  bent  himself  double  and  almost  groaned 
aloud,  for  the  child  himself  knew  nothing  about  the 
plexus  near  the  stomach,  neither  did  he  know  that 
wherever  fibers  are  thickest,  there  it  hurts  most  to 
be  punched.  The  boy's  brother,  fourteen  years  old, 
understood  the  situation  perfectly.  "  Because,"  as  he 
said,  "  you  see  it  hurts  awfully  to  be  thumped  in  your 
stomach  like  that." 

But  all  this  has  to  do  with  the  outside  of  the 
stomach.  Now  recall  Dr.  Cannon's  experiments  with 
cats.  Think  of  the  close  connection  which  he  dis- 
covered between  the  state  of  the  mind  and  the  work 
the  stomach  is  willing  to  do,  and  do  not  forget  that 
it  is  through  nerves  alone  that  the  mind  can  ever 
affect  the  stomach  in  this  way  or  that. 

Good  Temper  and  Digestion.  A  friend  of  mine  says 
that  many  a  time  when  he  was  young  he  himself  had 
the  cat's  experience.  He  was  quick-tempered,  nervous, 
and  excitable,  and  he  found  that  if  he  lost  his  temper 
while  he  was  eating,  or  if  he  even  became  unpleasantly 
excited,  he  immediately  felt  as  if  all  the  food  in  his 
stomach  had  turned  itself  into  a  weight  of  lead  that 
could  not  be  dislodged. 

Sometimes  his  stomach  even  went  so  far  in  its 
rebellion  as  to  force  up  everything  he  had  swallowed. 


256        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Experiences  of  this  sort  taught  the  boy  one  of  the  great 
lessons  of  his  life  —  that  he  must  keep  calm  and  serene 
at  mealtime.  Later  he  learned  that,  in  thousands  of 
cases,  bad  digestion  comes  from  a  bad  disposition,  and 
not  a  bad  disposition  from  bad  digestion,  as  so  many 
imagine. 

Why  Happiness  Helps  the  Body.  From  these  and 
other  observations  and  experiments  scientists  find  four 
good  reasons  why  happiness  helps  not  only  the  stomach 
but  all  other  parts  of  the  body  too. 

1.  A  happy  state  of  mind  affects  the  ganglia  in 
such   a   way   that    they    compel    the    small    blood 
vessels  to  expand.   This  allows  fresh  blood  to  flow 
easily  through  them. 

2.  A  happy  state  of  mind  affects  the  nerves  that 
control   the   lungs.     They   inhale   more   air.     This 
means   that   they  get   more    oxygen ;   and  this,  in 
turn,   means   that   the    blood    is   more   completely 
purified  in  the  lungs. 

3.  A  happy  state  of  mind  affects  the  ganglia  that 
control  the  heart,  making  it  beat  faster;  this  forces 
fresh    blood    rapidly  through    the   expanded    blood 
vessels.   And  rapidly  moving  blood  gives  rich  nour- 
ishment to  nerve  cell  and  muscle,  making  it  possible 
for  them  to  do  good,  energetic  work. 

4.  A  happy  state  of  mind  affects  the  ganglia  of 
the  stomach  so  promptly  that  its  churning  is  better 


HAPPINESS,  HEALTH,  AND  THE  GANGLIA        257 

done ;  while,  at  the  same  time,  more  gastric  juice 
pours  in  to  help  digestion  along. 

A  cheerful  schoolroom,  lively  games,  pleasant  friends, 
becoming  clothes,  comfortable  travel  by  land  and  by 
water  —  anything  that  makes  us  happy  without  doing 
us  harm  is  a  help  to  the  body  through  the  sympa- 
thetic ganglia. 

We  now  see  why  it  is  that  we  learn  our  lessons 
faster,  recite  them  better,  and  are  quicker-witted  in 
every  direction  when  we  are  happy  than  when  we  are 
unhappy.  It  is  simply  because  in  the  former  state  every 
organ  in  the  body  is  doing  its  best  work,  and  because 
the  brain  gets  the  benefit  of  it  all  through  an  improved 
blood  supply.  The  serious  fact  is  that  the  human 
machine  is  so  delicately  balanced  that  when  even  the 
smallest  part  of  it  fails,  the  whole  may  hitch  and  halt. 
Wear  out  the  fire  box  or  the  boiler  of  an  engine,  and  no 
matter  how  perfect  the  rest  of  the  machine  may  be,  it 
will  run  no  better  than  a  worn-out  affair  that  is  rusted 
in  every  joint. 

It  matters  not  where  the  hitch  in  the  human  machine 
begins  —  whether  with  too  much  food,  too  little  masti- 
cation, too  little  exercise,  too  much  worry,  excitement, 
anger,  fear,  or  torment  of  any  mental  sort ;  for  wherever 
the  start  may  be,  the  feelings  are  sure  to  be  pulled  into 
the  reckoning  erelong,  and  after  that  the  trouble  is 
increased  tenfold. 


258        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Service  from  the  Ganglia.  It  is  evident,  then,  that  we 
have  within  our  own  reach  methods  for  securing  good 
service  from  our  sympathetic  ganglia. 

1.  To  avoid  as  if  it  were  a  poison  each  thought 
and  emotion   that   saps  the   vigor  of   the   ganglia 
—  hatred,    malice,    envy,    jealousy,    anger,    despair, 
discouragement,  anxiety,  worry,  fear. 

2.  To  help  the  ganglia  through  love,  joy,  hope, 
courage,  faith,  trust,  belief  in  others,  belief  in  our- 
selves, good  cheer. 

3.  To  obey  all  the  laws  of  health  that  we  know 
anything  about. 

It  was  in  studying  this  last  point  that  Professor 
Kraepelin  and  others  came  to  their  conclusions  about 
the  effect  of  alcohol  on  nerve  tissue  and  efficiency,  as 
described  in  the  next  chapter. 

QUESTIONS 

1.  What  control  have  you  over  the  beating  of  your  heart?  over 
your  pulsing  arteries?  2.  If  you  should  command  the  stomach  to 
stop  digesting  its  food  contents,  what  result  would  there  be?  3.  What 
part  of  the  nervous  system  has  charge  of  internal  bodily  activities  ? 

4.  How  many  ganglia  are  there  in  the  sympathetic  nervous  system  ? 

5.  Where  do  they  lie?    6.   How  are  these  ganglia  connected  with  each 
other?    7.  Where  do  the  cell  bodies  of  the  ganglia  send  their  fibers? 
8.  When  fibers  are  very  closely  woven  together  in  a  network,  what  do 
they  form  ?    9.  When  a  man  is  punched  in  the  stomach,  which  plexus 
of  nerves  suffers  ?    10.  How  can  the  mind  influence  the  stomach  ? 


HAPPINESS,  HEALTH,  AND  THE  GANGLIA        259 

11.  What  was  Dr.  Cannon's  discovery  about  the  state  of  a  cat's 
feelings  and  the  work  of  a  cat's  stomach?  12.  What  similar  discov- 
ery did  a  man  make  about  his  own  state  of  mind  and  his  digestion  ? 
13.  What  effect  does  a  happy  state  of  mind  have  on  the  blood  vessels  ? 
on  the  lungs  ?  on  the  heart  ?  on  the  stomach  ?  14.  What  can  you  say 
about  anything  that  makes  us  happy  without  doing  us  harm  ?  15.  Why 
is  it  that  we  do  better  work  both  with  the  mind  and  with  the  body  when 
we  are  happy  than  when  we  are  unhappy?  16.  For  the  sake  of  the 
sympathetic  ganglia,  which  emotions  should  we  shun  ?  17 .  Which  emo- 
tions will  help  these  ganglia  ? 


CHAPTER  XVIII 
ALCOHOL  AND  EFFICIENCY 

Tests  made  with  Students.  Several  years  ago  Professor 
Kraepelin  of  the  University  of  Heidelberg,  in  Germany, 
did  some  experimenting  in  connection  with  the  students 
of  the  place.  He  was  just  the  one  to  carry  on  the  experi- 
ments, because  he  had  already  made  a  special  study  of 
the  nervous  system,  and  because  in  all  parts  of  the  world 
scientific  men  recognize  the  authority  of  his  name.  He 
himself  says  that  he  really  wished  to  save  a  little  of 
the  reputation  of  wine  and  beer,  for  he  saw  that  science 
was  crowding  pretty  hard  against  every  drink  containing 
alcohol. 

In  experimenting  with  his  students  Professor  Kraepe- 
lin always  gave  small  doses.  He  knew,  as  we  do,  that 
those  who  use  alcohol  frequently  in  large  doses  ruin  their 
lives  hopelessly.  Proofs  of  this  are  on  every  side  in  every 
land.  There  are,  however,  thousands  of  honest  people 
who  heartily  believe  that  alcohol  taken  in  small  doses  is 
a  help  on  all  sorts  of  occasions.  It  was  in  this  direction, 
therefore,  that  Professor  Kraepelin  experimented. 

Various  university  students  were  eager  to  know  facts, 

willing  to  be  tested,  and  quite  ready  to  drink  or  not  to 

260 


ALCOHOL  AND  EFFICIENCY  261 

drink,  according  as  the  progress  of  the  investigation 
required.  One  test  had  to  do  with  a  man's  quickness  in 
adding  up  columns  of  figures  for  half  an  hour  a  day 
during  six  days.  Those  being  tested  without  alcohol 
added  their  figures  as  rapidly  and  correctly  as  they 
could.  Then  the  alcohol  period  began,  and  for  thirteen 
days  the  same  students  used  alcohol  and  continued 
to  spend  the  half  hour  a  day  at  their  addition  tables. 
The  work  went  more  and  more  slowly,  until  the  nine- 
teenth day.  Alcohol  was  then  dropped.  The  men  con- 
tinued to  add,  and  there  was  immediate  and  marked 
improvement  in  the  work  they  did.  This  continued  until 
the  twenty-sixth  day,  when  they  returned  to  alcohol,  and 
once  again  there  was  a  change  for  the  worse. 

Thus  the  seesaw  between  alcohol  and  no  alcohol  went 
on  until  no  doubt  remained.  It  was  clear  to  all  that  the 
men  always  did  poorer  work  during  the  alcohol  period 
and  better  work  when  they  had  no  alcohol. 

Tests  made  with  Typesetters.  There  was  also  the  test 
with  the  typesetters  in  Heidelberg.  Dr.  Aschaffenburg 
carried  on  this  set  of  experiments.  Four  skilled  men 
were  chosen.  Three  were  in  the  habit  of r  using  alcohol 
in  small  amounts,  the  fourth  acknowledged  that  he  took 
too  much  once  in  a  while,  but  all  were  ready  to  go  with- 
out it  or  to  take  it,  as  the  tests  demanded.  Indeed  all 
four  men  were  anxious  to  know  whether  they  could  do 
swifter  and  better  work  with  the  alcohol  or  without  it. 


262        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

The  amount  which  Dr.  Aschaffenburg  gave  them  on 
the  days  when  they  took  alcohol  was  one  ounce  and  a 
quarter;  that  is,  the  wine  which  they  drank  had  about 
two  and  a  half  tablespoonfuls  of  alcohol  in  it. 

The  men  drank  it  fifteen  minutes  before  they  began 
their  typesetting.  For  fifteen  minutes  each  day  they 
worked  at  full  speed.  Each  did  what  he  could  to  set 
up  as  much  type  as  possible;  and  yet,  as  shown  in  the 
illustration  on  the  next  page,  in  every  case  but  one 
alcohol  hindered  and  did  not  help  him. 

But — and  here  we  meet  a  curious  fact — in  every  case 
the  men  themselves  thought  they  were  doing  better  and 
swifter  work  when  they  used  alcohol  than  when  they  did 
not  use  it.  Indeed  this  is  the  usual  belief  of  all  who  use 
alcohol.  Still,  many  careful  experiments  prove  that  the 
opposite  is  true. 

Experiments  with  Soldiers.  Sweden  has  turned  special 
attention  to  her  soldiers.  She  wishes  to  know  whether 
a  glass  of  wine  or  beer  taken  before  the  shooting  begins 
will  help  or  hinder  a  soldier  who  tries  to  hit  the  enemy. 

Lieutenant  Rengt  Boy  carried  on  the  experiments. 
The  soldiers  selected  were  picked  men,  all  fine  marks- 
men. Their  targets  were  two  hundreds 'yards  away,  and 
guns  and  rifles  were  used.  On  different  days  the  men, 
in  groups  of  six,  were  tested  with  alcohol  and  without 
it.  The  amount  of  alcohol  given  was  about  three  table- 
spoonfuls.  This  was  taken  in  the  shape  of  wine  or  beer, 


NO.  OF  LETTERS 
SET  UP 


3000 
2950- 
2900 


2750 
2700 


2500 
2450 


2150 
2100 
2050 
2000 
1950 
1900 
1850 
1800 
1750 
1700 
1650 
1600 

••  NON-ALCOHOL  DAY        ES3  ALCOHOL  DAY 

THE  RECORDS  OF  FOUR  MEN 

Each  group  of  four  columns  shows  the  work  of  the  same  man  for 

four  successive  days.   Black  columns  show  how  many  letters  they  set 

up  on  non-alcohol  days.   Dotted  columns  show  how  many  letters  they 

set  up  on  alcohol  days 


263 


264        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

sometimes  the  night  before,  sometimes  within  an  hour 
of  the  target  practice.  The  result  of  it  all  was  the  dis- 
covery that  in  every  instance  each  man  in  each  group 
did  his  quickest  firing  and  his  best  hitting  when  he 
had  had  no  alcohol  whatever  for  two  or  three  days 


TARGET  PRACTICE  FOR  SWEDISH  SOLDIERS 
They  need  steady  nerves 

beforehand,  and  that  he  did  his  poorest  work  when  he 
had  used  alcohol  at  any  time  within  twenty-four  hours. 
As  staff  surgeon  Mernetsch  reports: 

When  under  alcohol  the  result  was  30  per  cent  less  hits  in  quick 
fire ;  and  the  men  always  thought  they  were  shooting  faster,  whilst 
actually  they  shot  much  more  slowly.  When  slow  aiming  was  allowed 
the  difference  even  went  to  50  per  cent. 


ALCOHOL  AND  EFFICIENCY  265 

Alcohol  and  the  Neuron.  With  these  facts  in  mind  we 
are  not  surprised  to  learn  that  the  condition  of  the  neuron 
of  the  drinker  is  often  quite  enough  to  explain  his 


CELLS  FROM  THE  SPINAL  CORD 

The  upper  cell  at  the  left  is  normal,  with  its  nucleus  in  the  center.  The  upper 
cell  at  the  right  is  dead ;  it  has  no  nucleus  whatever.  The  other  cells  are  swollen 
and  the  nucleus  is  pushed  far  to  one  side.  These  diseased  cells  were  taken  from 
alcoholic  persons  who  died  in  Claybury  Asylum,  England.  They  were  drawn  by 
Dr.  Mott  for  Sir  Victor  Horsley 

failures.  The  illustration  tells  the  whole  story.  Compare 
that  clean-cut,  trim,  normal  cell,  taken  from  a  healthy 
brain,  with  the  ruined  cells  from  alcoholic  brains. 


266        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

QUESTIONS 

1.  What  tests  did  Professor  Kraepelin  of  Germany  make  with 
students  ?  2.  What  do  some  people  believe  about  the  helpful  effect  of 
wine  and  beer?  3.  Describe  the  German  tests  in  adding  columns  of 
figures  ?  4.  What  did  these  tests  prove  about  the  effect  of  using  alco- 
hol when  one  wishes  to  do  quick,  accurate  work  ?  5.  Tell  about  the 
alcohol  tests  made  .with  typesetters.  6.  How  much  alcohol  did  the  men 
take  on  the  days  when  it  was  given?  7.  Describe  the  experiment. 
8.  What  did  the  men  themselves  think  about  the  work  they  did  after 
using  alcohol  ?  9.  What  did  this  experiment  prove  ?  10.  What  did 
Sweden  wish  to  discover  about  wine  and  beer?  11.  What  kind  of 
men  were  selected  for  the  experiment?  12.  Describe  the  experiment. 
13.  How  much  alcohol  was  used  ?  14.  What  did  the  staff  surgeon 
say  about  this  experiment? 

15.  Describe  the  appearance  of  normal,  healthy  brain  cells;  of  cells 
ruined  by  alcohol.  16.  What  sort  of  work  is  done  by  a  damaged  brain 
cell?  17.  Since  we  cannot  see  the  neurons  in  a  living  brain,  how  can 
we  tell  what  their  real  condition  is  ? 


CHAPTER  XIX 

THE  MENACE  OF  THE  MICROBE 

The  Public  Drinking  Cup.  On  the  first  of  September, 
1909,  the  Board  of  Health  of  the  state  of  Kansas  began 
to  enforce  a  new  law : 

The  use  of  the  common  drinking  cup  on  railroad  trains,  in  railroad 
stations,  in  the  public  and  private  schools,  and  in  the  state  educational 
institutions  of  the  state  of  Kansas  is  hereby  prohibited,  from  and  after 
September  i,  1909. 

No  person  or  corporation  in  charge  or  control  of  any  railroad  train 
or  station,  or  public  or  private  school,  or  state  educational  institution 
shall  furnish  any  drinking  cup  for  public  use,  and  no  such  person  or  cor- 
poration shall  permit  on  said  railroad  train,  station,  or  at  said  public  or 
private  school,  or  state  educational  institution  the  common  use  of  the 
drinking  cup. 

When  this  law  went  into  effect,  and  when  thirsty 
people  arrived  at  the  station  and  found  that  they  must 
have  their  own  drinking  cups,  some  of  them  were  dis- 
pleased. They  thought  the  Board  of  Health  was  growing 
altogether  too  particular.  But  read  the  following  facts 
and  judge  the  case  for  yourself;  I  quote  the  account 
from  a  report  that  was  printed  in  February,  1909. 

Professor  Davidson  of  Lafayette  College  asked  ten  boys  to  apply  the 
upper  lip  to  pieces  of  flat,  clean  glass  in  the  same  way  as  they  would 

267 


268       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

touch  a  cup  in  drinking.  These  glass  slips  were  then  given  a  thorough 
microscopic  examination,  and  they  showed  an  average  of  about  one  hun- 
dred human  cells,  or  bits  of  skin,  and  seventy-five  thousand  bacteria1  to 
each  slip.  This  from  one  application  of  the  lip. 

A  cup  which  had  been  used  in  a  high  school  for  several  months  with- 
out being  washed  was  lined  inside  with  a  brownish  deposit.  Under  the 
microscope  this  proved  to  be  composed  of  particles  of  mud,  thousands 
of  bits  of  dead  skin,  and  millions  of  bacteria,  among  which  were  scores 
of  germs  corresponding  in  all  details  to  those  of  tuberculosis.  Some  of 
this  sediment  was  injected  under  the  skin  of  a  healthy  guinea  pig,  and 
in  forty  hours  the  animal  died.  A  post-mortem  examination  revealed 
the  fact  that  death  was  due  to  the  presence  of  a  sufficient  number  of 
pneumonia  germs  to  cause  blood  poisoning. 

A  second  guinea  pig  inoculated  with  the  cup  sediment  developed  tuber- 
culosis. Careful  inquiry  proved  that  several  pupils  in  the  school  from 
which  the  cup  was  taken  were  then  sufferers  from  this  dread  disease. 

Before  going  on  with  this  chapter,  give  attention  to 
the  following  statements: 

What  a  Microbe  Is.  The  word  microbe  means  "small 
life."  A  microbe  is  any  living  plant  or  animal  which  is 
too  small  to  be  seen  without  a  magnifying  glass.  Many 
people  speak  of  microbes  as  germs.  This  is  quite  cor- 
rect, for  both  words  refer  to  the  same  tiny  bits  of  plant 
and  animal  life.  Most  microbes  are  harmless.  Some 
microbes  give  us  disease  of  one  kind  or  another.  These 
are  called  disease  microbes.  Each  microbe  disease  is 
caused  by  its  own  special  kind  of  microbe.  These 
microbes  do  their  mischief  after  they  enter  the  body. 
Microbe  diseases  are  called  preventable,  because  if  we 

1  Different  kinds  of  microbes. 


THE  MENACE  OF  THE  MICROBE  269 

destroy  the  microbes,  or  prevent  them  from  attacking 
us,  we  are  sure  to  escape  the  malady.  By  keeping  the 
body  in  vigorous  condition  we  may  avoid  illness  even 
after  certain  microbes  have  attacked  us. 

How  Microbes  Attack  the  Body.   Microbes  find  entrance 
to  the  body  by  one  or  the  other  of  four  different  roads. 

1.  Through  the  nose  and  lungs,  in  air  laden  with 
dust  mixed  with  microbes,  for  example.    Any  man 
who  spits  where  the  saliva  may  dry  and  be  blown 
about  is  bringing  danger  to  the  air  which  other 
people  must  breathe.    He  who  sneezes  or  coughs 
without  a  handkerchief  held   to  his  face   is  doing 
the  same  thing.    He  is  scattering  microbes  in  the 
air,  and  if  he  has  a  cold  or  tuberculosis,  the  disease 
microbes  are  able  to  give  the   same  cold  or  con- 
sumption to  those  who  breathe  the  air  after  him. 

2.  Through  the  mouth,  in  food  and  drink  or  in 
anything  which  may  be  put  into  the  mouth  —  the 
point  of  a  pencil,  a  half-eaten  apple,  an  unwashed 
spoon  or  fork,  fingers  moistened  to  turn  a  page. 
Even  a  kiss  on  the  lips  may  be  a  serious  matter. 

3.  Through  contact  with  microbes  from  the  skin 
of  a  person  just  recovering  from  such  diseases  as 
smallpox,  chicken  pox,  scarlet  fever,  and   measles. 

4.  Through  the  aid  of  creatures  that  puncture  the 
skin  and  leave  disease  microbes  in  the  blood.    Mos- 
quitoes do  this,  one  kind  giving  us  malaria,  another 


270       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

kind  giving  us  yellow  fever.    We  shall  study  the 
*      subject  later.    Fleas  carry  bubonic  plague  from  rats 

to  human  beings.    The  stable  fly  carries  infantile 

paralysis   from    person    to   person.    Lice   probably 

carry  typhus  fever. 

Now  it  is  because  of  such  facts  as  these  that  we  guard 
ourselves  from  disease  microbes  at  every  possible  point. 
When  you  next  take  up  a  public  drinking  cup,  think  of 
the  microbes  that  may  be  on  it.  When  drinking  at  a 
sanitary  fountain  the  lips  touch  nothing  but  water,  and 
no  harm  can  be  done  either  to  yourself  or  to  those  who 
may  follow  you.  The  individual  drinking  cup  is  equally 
safe. 

Protection  for  the  Eyes.  But  the  public  drinking  cup 
is  not  the  only  danger  that  threatens  school  children. 
Think  of  pink  eye  and  trachoma,  described  in  Health 
and  Safety.  They  always  go  by  the  road  of  touch.  No 
healthy  eyes  will  take  either  disease  unless  they  are 
touched  by  something  which  has  already  touched  dis- 
eased eyes  —  for  example,  fingers,  a  contaminated  towel, 
or  a  handkerchief. 

My  next-door  neighbor  seems  to  know  this  already. 
He  came  from  school  the  other  day  and  said,  "  Pink  eye 
has  started  in  school,  but  I  'm  not  going  to  catch  it." 
"  How  will  you  escape  ?  "  I  asked.  '  That 's  simple 
enough,"  he  answered ;  "  I  '11  keep  my  hands  away  from 
my  eyes ;  I  '11  never  touch  them  with  anything  except 


THE  MENACE  OF  THE  MICROBE  271 

my  own  towel  at  home.  I  '11  have  to  do  this,  because  at 
school  my  hands  touch  what  other  boys  have  touched, 
and  I  never  know  what  microbes  may  be  on  them."  I 
commended  my  neighbor  and  was  glad  to  see  that  he 
did  save  himself  from  pink  eye,  although  his  best  friends 
had  it.  The  probability  is  that  they  not  only  touched 
their  eyes  with  their  hands  but  also  used  the  common 
towel.  This  should  be  banished  from  every  schoolhouse. 
Even  books,  used  by  others,  may  bring  disease  microbes 
to  us.  If  possible,  avoid  books  that  have  become  soiled 
through  long  use. 

So  much,  then,  for  the  direct  ways  by  which  microbes 
may  travel  from  person  to  person ;  but  what  about  the 
indirect  road? 

Why  we  Object  to  Flies.  Think  of  our  numberless, 
small,  unwelcome  neighbors,  the  flies.  Why  do  intel- 
ligent people  object  to  the  presence  of  flies  in  kitchen, 
pantry,  and  dining  room  ?  Why  do  we  carry  on  an  end- 
less fight  against  them  ?  For  the  simple  reason  that  flies 
never  either  wash  or  wipe  their  feet.  Yet  think  for  a 
moment  where  those  tiny  feet  travel.  Where  dead  things 
lie,  where  filth  is  worst,  where  disease  has  been,  there  do 
we  find  flies  in  greatest  numbers.  And  it  is  always  in 
just  such  places  that  they  lay  their  eggs  and  multiply. 

Study  the  subject  for  yourself.  Look  at  the  open 
garbage  pail  in  the  summer,  or  at  a  pile  of  decaying 
waste  anywhere.  Notice  the  multitudes  of  flies  there, 


272        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

then  notice  where  flies  stand  thickest  in  your  home. 
From  the  barnyard,  where  they  multiply  fastest  in  horse 
manure,  or  from  a  sewage  farm  with  feet  covered  with 
typhoid  microbes,  they  may  fly  to  your  dining  table  and 
leave  living  microbes  on  bread,  beef,  cake,  candy  —  on 
anything  you  eat.  For  in  the  line  of  food,  flies  enjoy  not 
our  waste  alone  but  also  whatever  we  have  prepared 
with  greatest  care  as  food 
for  ourselves.  They  stand 
on  this  dainty  food  of  ours 
with  their  soiled  feet,  and 


THE  HOUSE  FLY 
<*>  egg ;  by  larva,  or  maggot ;  c,  pupa  case,  or  puparium  ;  d,  adult  male.  (All  enlarged) 

we  swallow  the  food  plus  the  microbes  which  mark  their 
footsteps.    This  danger  from  the  fly  is  very  real. 

Of  every  hundred  soldiers  who  died  in  the  Spanish- 
American  War,  twenty  were  killed  by  bullets,  eighty  by 
microbes.  And  over  and  over  again  the  doctors  blamed 
the  feet  of  the  flies  for  having  put  typhoid  microbes  on 
the  food  the  soldiers  ate. 


THE  MENACE  OF  THE  MICROBE  273 

What  Flies  Eat.  But  aside  from  the  microbes  they 
carry  on  their  feet,  there  is  mischief  done  by  flies 
through  the  refuse  which  they  are  willing  to  eat.  Dr. 
Lord,  a  scientist,  allowed  flies  to  eat  sputum  from  the 
lungs  of  a  man  who  had  tuberculosis.  Those  flies 


WHERE  FLIES  MULTIPLY 

then  deposited  their  flyspecks,  and  fifteen  days  later 
Dr.  Lord  examined  the  specks  and  found  living  tubercle 
bacilli  in  them.  Those  microbes  of  tuberculosis  had 
been  taken  into  the  mouth  of  the  fly,  had  gone  safely 
through  its  body,  were  alive  when  they  left  the  body  as 
flyspecks,  and  after  fifteen  days  were  as  vigorous  as 


274        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

ever  and  ready  to  threaten  the  living  tissue  of  human 
beings.  Think  of  the  flyspecks  which  are  left  on  our 
food  when  flies  stand  upon  it. 

Safety  through  Carefulness.  Such  facts  as  these  ex- 
plain the  widespread  fight  against  the  ever-present  fly. 
We  have  no  objection  to  the  little  creatures  themselves, 
but  we  greatly  object  to  the  diseases  which  they  may  in- 
flict upon  us.  We  therefore  do  what  we  can  to  reduce 
their  numbers. 

A  careful  housewife  keeps  the  garbage  pail  closely 
covered,  that  flies  may  not  enter  and  lay  their  eggs 
there.  She  has  it  emptied  often  and  scalded,  that  such 
eggs  as  may  have  been  laid  on  the  food  before  it  went 
into  the  pail  may  be  killed  and  never  allowed  to  hatch. 
She  screens  doors  and  windows  and  never  allows  a  fly, 
living  or  dead,  to  find  lodgment  on  her  food,  either  in 
kitchen,  in  pantry,  or  on  the  dining  table. 

A  careful  grocer  meets  this  same  situation  in  the 
same  way.  If  he  must  display  his  foodstuffs  to  charm 
the  passer-by,  he  puts  them  under  glass  or  stretches  net- 
ting about  them.  He  knows  that  the  sight  of  flies  on  his 
foods  will  drive  the  careful  housewife  from  his  door. 

A  careful  man  who  keeps  horses  sees  to  it  that  the 
stables  are  kept  clean.  He  knows  that,  whenever  pos- 
sible, flies  lay  their  eggs  in  such  places ;  that  each  egg 
hatches  out  into  a  tiny  maggot;  that  maggots  soon 
turn  into  full-fledged  flies,  ready  to  lay  eggs  for  another 


THE  MENACE  OF  THE  MICROBE  275 

generation;  and  that  in  our  fight  against  the  fly  the 
main  point  is  to  keep  the  creatures  from  multiplying. 

A  careful  city  takes  the  same  facts  about  flies  into 
account.  It  allows  no  piles  of  rubbish  to  stand  about;  it 
allows  no  dead  animals  to  stay  unburied  and  no  stables  to 
remain  uncleaned.  It  insists  on  having  clean  streets,  and 
yards  with  no  neglected  refuse  in  which  flies  may  lay 
their  eggs.  And  it  is  the  desire  for  health  that  explains 
this  passion  for  clean  things  which  now  moves  all  civil- 
ized peoples.  We  wish  to  breathe  clean  air  in  clean 
streets;  we  wish  to  eat  clean  food  in  which  no  disease 
microbes  may  be  found ;  we  wish  to  be  rid  of  city  waste 
promptly  because  we  are  not  willing  to  run  the  risk  of 
increasing  danger  for  ourselves  from  microbes  which  may 
be  in  it  and  which  may  threaten  us  later. 

In  city  and  country  alike,  the  intelligence  of  the  citi- 
zens decides  what  their  own  life  and  death  prospects 
shall  be,  for  sanitation  controls  the  death  rate. 

QUESTIONS 

1.  Give  what  you  can  of  the  Kansas  law  about  the  common  drink- 
ing cup.  2.  Describe  experiments  made  with  pieces  of  glass  that  had 
touched  the  lips.  3.  Describe  the  appearance  of  the  cup  used  in  the 
high  school.  4.  Tell  about  the  experiments  made  on  a  guinea  pig. 
5.  What  does  the  word  " microbe"  mean?  6.  Are  most  microbes 
harmful  or  harmless  ?  7 .  Why  are  certain  microbes  called  disease 
microbes  ?  8.  Why  are  microbe  diseases  called  preventable  ?  9.  Why 
should  we  keep  the  body  in  vigorous  condition? 


276        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

10.  By  how  many  roads  may  microbes  enter  the  body?  11.  Give 
several  ways  by  which  people  can  bring  danger  to  the  air  which  other 
people  breathe.  12.  Mention  ways  by  which  microbes  may  enter  the 
mouth.  13.  What  objection  is  there  to  touching  the  point  of  a  pencil 
to  the  tongue?  to  using  unwashed  forks  and  spoons  after  another  per- 
son ?  14.  Why  not  turn  a  page  with  a  finger  moistened  at  the  lips  ? 
15.  What  diseases  are  contagious  through  the  skin?  16.  What  small 
creatures  give  us  disease  by  puncturing  the  skin  and  leaving  disease 
microbes  in  the  blood?  17.  Why  have  people  adopted  the  sanitary 
drinking  fountain  ?  18.  How  does  it  help  ?  19.  How  may  eye  trouble 
be  passed  from  person  to  person  ?  20.  How  may  one  avoid  taking  a 
contagious  eye  disease  ? 

21.  Why  do  we  object  to  flies?  22.  Give  reasons  why  garbage, 
refuse,  and  decaying  waste  should  never  be  allowed  to  accumulate. 
23.  Where  do  flies  multiply  fastest?  24.  What  did  the  doctors  say 
about  the  death  of  soldiers  in  the  Spanish- American  War  ?  25.  Describe 
Dr.  Lord's  experiment  with  flies.  26.  What  does  a  careful  housekeeper 
do  about  the  garbage  pail,  etc.  ?  27.  How  does  the  careful  grocer 
guard  his  foodstuffs  ?  28.  What  does  a  careful  man  do  about  his  horses 
and  his  stables  ?  29.  What  ought  he  to  know  about  fly  eggs  and  their 
history  ?  30.  What  does  a  careful  city  do  to  protect  itself  from  flies  ? 


CHAPTER  XX 

SANITATION 

Country  Conditions.  If  you  live  in  the  country,  step 
out  of  doors  and  see  what  the  sanitary  conditions  of 
your  surroundings  are.  Examine  both  the  inside  and 
the  outside  of  the  barn,  the  stable,  the  hen  yard,  the 
outhouse,  and  the  pigpen.  Notice  the  location  of  the 
well.  See  if  it  is  near  enough  to  other  buildings  to 
make  it  possible  for  contamination  to  soak  down  and 
across  until  it  reaches  your  drinking-water.  Look  for 
flies  and  their  breeding  places.  Decide  what  ought  to 
be  done  to  get  rid  of  them.  How  about  the  rubbish 
heaps  and  the  garbage  pail  ?  Do  you  think  everything 
is  properly  clean  about  the  place  ? 

City  Surroundings.  If  your  home  is  in  the  city,  go 
with  some  grown  friend  to  the  most  crowded  and  un- 
tidy part.  Enter  any  tenement  house  and  make  discov- 
eries for  yourself.  You  will  find  that  city  crowding  often 
reaches  a  perilous  point;  that  even  when  people  object 
to  miserable  surroundings,  they  are  sometimes  obliged 
to  use  dark  halls,  dark  cellars,  and  wretched  bath- 
rooms. The  real  owners  of  these  houses  seem  to  act  as 

if  they  thought  the  darkness  would  save  their  tenants 

277 


278        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

from  disease  as  well  as  from  disgrace.  Yet  in  such 
places  everything  helps  disease  along.  Gas  pipes  leak 
and  sewer  pipes  are  out  of  order;  the  air  grows  heavy 
with  carbon  dioxide,  with  illuminating  gas,  with  foul 
gases  from  broken  sewers,  with  the  smell  of  unwashed 
people  and  unclean  clothes.  At  the  same  time  damp- 
ness adds  to  the  danger.  Even  in  our  day  there  are 
thousands  of  people  who  do  not  know  that  dampness, 
darkness,  and  dirt  are  just  the  three  conditions  that  are 
best  for  microbes  and  worst  for  men. 

The  Meaning  of  Sanitation.  And  it  is  because  all  this 
is  so  true  that  nowadays  we  hear  so  much  about  sanita- 
tion—  the  science  of  securing  conditions  which  favor 
health.  The  problem  itself  faces  both  the  country  home 
and  the  city  tenement.  And  in  studying  it  we  find  that 
always  and  everywhere  we  are  called  upon  to  guard  three 
things  in  connection  with  our  homes. 

1.  The  air  we  breathe.    Neighbors  cannot  allow 
each  other  to  contaminate  the  air  with  their  disease 
microbes;  neither  can  they  permit  the  presence  of 
unpleasant  odors  from  decaying  garbage  or  from 
pigpens,  stables,  and  the  like. 

2.  The  water  we  drink.    This  must  be  so  pro- 
tected that  even  if  a  neighbor  in  the  country  has 
typhoid  fever,  no  waste  from  his  body  shall  have 
the   slightest  chance   to   reach    the    drinking-water 
of  the  neighborhood. 


SANITATION  279 

3.  The  food  we  eat.  This  must  be  fresh  and  pure, 
without  any  sign  of  adulteration.  It  must  be  pro- 
tected both  by  state  and  national  laws  and  by  the 
cooperation  of  all  those  who  sell  foodstuffs  to  each 
other. 

Cleanliness  the  Watchword.  At  the  present  time  cleanli- 
ness is  indeed  the  watchword  for  every  community  — 
clean  air,  clean  water,  clean  food,  clean  surroundings  of 
every  sort.  But  it  sometimes  seems  as  if  people  in  the 
country  had  to  work  harder  to  gain  this  cleanliness  than 
those  in  the  city.  Note  the  following  contrasts: 

1.  In  the  country  each  home  must  get  rid  of  its 
own  garbage,  parings,  fruit  skins,  table  waste,  bones, 
etc.    All  this  must  be  carried  to  the  pigs,  or  it  must 
be  deeply  buried  and  covered  lest  it  give  off  an  odor 
as  it  decays.    In  the  city  all  such  waste  goes  into 
a  garbage  can,  and  a  man  from  the  health  depart- 
ment takes  it  away.    We  have  no  further  thought 
about  it  except  to  keep  the  pail  scalded  and  covered. 

2.  In  the  country  the  kitchen  may  lack  a  sink, 
in  which  case  waste  water  must  be  carried  out  and 
thrown  in  a  sunshiny  place,  that  it  may  not  become 
a  gathering  place  for  flies.   The  outhouse  must  be 
strictly  guarded  from  flies  and  kept  in  a  sanitary 
condition   by   the    use   of   lime.     In    the    city   the 
waste    from    every    sink    and    bathroom    is    carried 
out  of  town  by  the  sewage  system. 


280       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

3.  In    the    country    such    dry    wastes    as    ashes, 
paper,  scraps  of  iron,  old  shoes,  rags,  etc.  must  be 
disposed  of  by  each  owner  as  best  he  can.    Some- 
times part  of  this  rubbish  is  burned,  part  buried. 
In  the  city  all  such  rubbish  is  packed  into  bags, 
and    at    stated    times   these    bags   are   carried    off 
and  disposed  of  by  the  workers  of  the  city  health 
department. 

4.  In    the    country   the    roads   often    suffer   sad 
neglect.    In   the   city,  men   of   the   street-cleaning 
department   do   the   work  and    are    paid  for  it  by 
the  taxes  of  the  citizens.    In  fact,  all  city  work  of 
every  department  is  paid  for  by  these  taxes. 

5.  In  the  country,  as  a  rule,  each  separate  home 
is  responsible  for  the  kind  of  water  the  family  must 
drink,  for  the  well  is  in  a  place  selected  by  the 
owner  of  the  house.    In   the  city,  water  comes  in 
pipes  from  out  of  town,  and  the  Board  of  Health 
decides  whether  or  not    this    supply    is   safe  from 
typhoid-fever  microbes. 

From  these  contrasts  it  looks  as  if  country  folk  had 
a  hard  time  and  city  folk  an  easy  time  with  their  sanita- 
tion problems.  But  turn  to  another  side  of  the  same 
subject. 

Sunshine  and  Air  in  Country  and  City.  Remember  that 
every  living  creature  should  be  surrounded  by  sunshine 
and  fresh  air  every  day.  Then  think  of  the  glorious 


SANITATION 


281 


chance  for  both  in  the  country,  and  of  the  poor  chance 
for  either  that  thousands  upon  thousands  of  city  people 
have.  Think  of  the  towering  tenement  houses,  where  the 
streets  between  are  like  deep  narrow  valleys,  and  where 
children  play  every  day  without  a  ray  of  sunshine  about 
them.  Think  of  the  thousands  upon  thousands  of  inside 


A  VILLAGE  HOME 

rooms  in  every  crowded  city,  where  no  outside  window 
ever  lets  in  air  and  sunshine.  In  1911  there  were  90,000 
such  rooms  in  New  York  City  alone.  Think  of  persons 
ill  in  such  places.  Think  of  the  dark  corners  and  the 
filthy  cellars  and  of  the  disease  microbes  safely  lodged 
and  living  in  them.  Think  of  all  the  babies  that  are  here 
robbed  of  every  chance  of  life  and  of  the  little  children 
who  must  surely  suffer  when  an  epidemic  comes. 


282        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

In  London  the  crowding  is  so  great  that  300,000  of 
its  citizens  live  in  tenements  of  one  room  for  a  family. 
Forty  thousand  of  these  live  5  in  a  single  room,  while 
8000  live  8  in  a  room.  Other  cities  are  crowded,  too. 


HOMES  IN  NEW  YORK  CITY 

Rear  Tenements  and  the  Death  Rate.  In  New  York 
City  the  darkest  arid  most  unwholesome  houses  are 
rear  tenements.  These  stand  so  close  behind  the  front 
tenements  that  the  distance  between  them  is  from  two 
inches  to  five  feet.  Of  course  each  building  keeps 
daylight  from  the  other,  but  at  the  same  time  the  rear 


SANITATION  283 

tenement  is  always  the  older,  the  more  unclean,  and  the 
more  neglected  of  the  two.  Mr.  R.  W.  De Forest  tells 
us  that  at  one  time,  in  these  rear  tenements,  one  baby 
died  for  every  five  that  were  born.  These  places  were 
then  called  "infant  slaughter  houses,"  because  of  the 
terrible  conditions  which  killed  the  children. 

New  Tenement  Regulations.  But,  in  course  of  time, 
reform  came.  A  new  tenement-house  department  was 
established,  and  it  made  better  building  regulations. 
The  new  requirements,  condensed  here,  are  worth  keep- 
ing in  mind  as  a  guide  for  the  building  of  any  home. 

No  room  without  a  window  opening  out  of  doors ;  good  light  and 
ventilation ;  halls  square,  broad,  light ;  stairs  neither  steep  nor  dark ; 
every  one  of  them  fireproof ;  separate  bathroom  arrangements  for  each 
family ;  courtyard  not  less  than  twelve  and  a  half  feet  wide  and  twenty- 
eight  feet  long ;  light  everywhere,  so  that  dust  and  rubbish  show  plainly 
and  microbes  have  little  chance. 

Parks,  Playgrounds,  etc.  Every  important  city  in 
the  land  is  bending  its  energies  in  the  direction  of 
sanitary  surroundings  for  all  the  citizens.  Such  sur- 
roundings require  clean  streets  and  sidewalks,  and  the 
prohibition  of  spitting;  houses  with  modern  plumbing, 
and  with  an  abundant  supply  of  sunlight  and  air;  pro- 
tection from  microbe  diseases ;  parks  and  playgrounds 
where  children  may  exercise  in  fresh  air  and  sun- 
shine ;  public  baths  where,  at  little  cost,  citizens  may 
refresh  themselves  through  cleanliness;  water  from 


284       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

sources  uncontaminated  by  human  wastes ;  food  which 
must  come  up  to  a  fixed  standard  of  purity  and  be  passed 
upon  by  city  inspectors;  pure  milk  from  tested  cows. 
In  most  cities  the  board  of  health  tries  to  give  to  its 
citizens  all  these  good  things,  and  it  is  for  us  to  find  out 


SWIMMING  POOL,  NEW  CURTIS  HALL  BUILDING,  JAMAICA  PLAIN  (MASS.) 
Indoors  the  year  round 

what  is   being   done   by  our  own  board  of  health  for 
the  protection  of  ourselves  and  our  neighbors. 

The  Sewage  System.  Even  go  as  far  as  to  find  out 
about  the  sewage  system  of  your  town.  Learn  how  the 
sewage  is  gathered,  where  it  is  deposited,  and  find  out 


SANITATION  285 

whether  there  is  any  risk  of  spoiling  the  water  or  the  air 
for  other  people.  Remember  that  flies  go  where  filth 
is  found,  and  that  if  sewage  leaks,  flies  will  discover  it 
and  will  bring  disease  germs  from  it  into  your  home. 
Careful  disposal  of  town  and  city  sewage  is  one  of 
the  most  important  of  sanitation  duties.  And  what  of 
sanitation  and  our  food  supply?  Here  country  and 
city  alike  are  '  helped  by  our  national  pure-food  laws. 

Pure-Food  Laws  and  Food  Inspection.  In  1906  the  gov- 
ernment of  the  United  States  passed  what  are  known 
as  the  pure-food  laws.  Even  before  this,  however,  many 
cities  had  their  food  inspectors,  who  hunted  out  and 
destroyed  unfit  food.  Not  so  very  long  ago  the  food 
inspectors  of  Cleveland,  Ohio,  sent  2500  pounds  of  un- 
fit meat  from  the  market  to  the  garbage  plant.  Later 
the  health  officers  of  the  same  city  seized  38  cattle, 
29  hogs,  4  sheep,  and  5  calves,  telling  the  owners  that 
the  animals  were  diseased  and  not  fit  to  be  sold  for  food. 
In  1907  the  inspectors  in  New  York  City  discovered 
and  destroyed  362,795  pounds  of  groceries  and  canned 
goods  which  were  unfit  for  use.  So  the  experiences  of 
diffe'rent  cities  might  be  multiplied. 

Danger  from  Dyes.  One  inspector  writes :  "  I  have 
seen  candy  samples  brought  to  the  laboratories  and 
boiled  down;  then  rags  were  dipped  in  the  stuff,  and 
after  the  rags  were  dried  no  amount  of  washing  would 
remove  the  dye."  Dr.  Kellogg  says  that  "  a  single  glass 


286        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

of  raspberry  soda  such  as  is  found  at  soda  fountains  was 
found  to  contain  sufficient  coal-tar  dye  to  color  two 
yards  of  woolen  cloth."  Now  the  objection  to  these  coal- 
tar  dyes  is  that  some  of  them  are  harmful.  It  is  best, 
therefore,  to  omit  them  from  our  fruit,  our  candies,  and 
our  bright-colored  drinks.  If  you  feel  suspicious  of  any 
special  bright-colored  canned  fruit,  test  the  liquid  for 
yourself.  Dip  a  bit  of  clean  white  cloth  into  it  and  let 
it  dry.  If  the  color  will  not  wash  out,  you  should  report 
to  a  food  inspector.  He  will  follow  the  matter  up  and 
decide  whether  or  not  the  color  is  due  to  the  fruit  itself 
or  to  a  dye. 

Canned  Food.  Food  canned  in  tin  should  never  be  left 
in  the  can  after  it  is  opened.  Canned  meat  should  be 
used  the  day  it  is  opened,  because  it  decays  soon.  Our 
food  supply  is  really  safer  than  it  has  been  for  years, 
because  food  inspectors  are  on  the  watch.  There  is  a 
standard  set  by  law  for  every  article  of  food  we  use 
—  for  flour,  sugar,  tea,  coffee,  canned  meats,  canned 
vegetables,  canned  fruit,  honey,  molasses,  butter,  maple 
sirup,  and  all  the  rest.  And  the  duty  of  the  inspector 
is  to  see  that  what  is  sold  corresponds  with  what  the  law 
requires.  Many  meat  markets,  fish  markets,  bakeries, 
and  groceries  that  were  careless  before  are  now  required 
to  be  clean  and  to  keep  the  food  they  sell  safe  from  flies, 
dust,  and  soiled  hands.  In  some  places  hands  are  not 
allowed  to  touch  bread  after  it  is  baked.  The  pure-food 


SANITATION  287 

law  also  requires  that  the  label  on  medicines,  sauces, 
catchups,  and  preserved  fruits  or  vegetables  shall  declare 
exactly  what  ingredients  are  in  them. 

Patent  Medicines.  At  the  great  exposition  in  San 
Francisco,  in  1915,  the  American  Medical  Association 
had  a  special  exhibition  to  show  how  much  alcohol 
there  is  in  different  kinds  of  patent  medicine.  It  was  a 
sorry  sight.  For  by  its  exhibition  the  Medical  Associa- 
tion showed  that  almost  all  patent  medicines  are  worse 
than  useless,  and  that  he  who  buys  and  uses  them  runs 
the  risk  of  injuring  his  health  seriously. 

No  disease  of  man  causes  more  despair  in  our  towns 
and  cities  than  tuberculosis.  We  therefore  turn  now  to 
study  its  cause  and  the  way  to  prevent  it. 

QUESTIONS 

I.  What  should  be  the  condition  of  barn,  stable,  hen  yard,  and  other 
outbuildings  in  the  country?    2.  Where   should   the  well  be  placed? 
3.   How  about  cleanliness  in  the  city?    4.  Visit  some  crowded  part  of 
it  and  describe  what  you  find.    5.  What  about  tall  tenements,  dark  halls, 
unpleasant  odors,  leaking  gas  pipes,  broken   sewers  ?    6.  What  three 
conditions  are  best  for  microbes  and  worst  for  men?    7.   What  three 
things  must  people  guard  in  connection  with  their  homes?    8.   How 
may  the  air  be  kept  pure  ?     9.    Why   should   water   be   kept   pure  ? 
10.  What  is  the  modern  watchword  for  every  community? 

I 1 .  What  do  people  do  with  their  garbage  in  the  country  ?  in  the 
city?    12.  What  do  people  do  about  their  sewage  in  the  country?  in 
the  city?    13.  What  do  people  do  with  their  dry  wastes  —  their  rubbish 
—  in  the  country?  in  the  city?    14.  What  about  street  cleaning  in 


288        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

country  and  city?  15.  Who  is  responsible  for  a  man's  drinking-water 
in  the  country?  in  the  city?  16.  In  these  five  sets  of  contrasts,  who 
seem  to  have  the  easiest  task  in  keeping  their  surroundings  sanitary, 
people  in  the  country  or  people  in  the  city?  17.  What  can  you  say 
about  the  need  of  sunshine  and  fresh  air  for  everybody  ?  18.  What 
chance  for  this  is  there  in  the  country  ?  in  the  city  ?  19.  Why  are  some 
city  streets  like  narrow,  sunless  valleys  ?  20.  How  much  sunshine  do 
children  get  who  play  in  the  streets  of  certain  cities?  21.  What  are 
rear  tenements?  22.  Describe  the  requirements  of  the  new  law  for 
tenement  houses. 

23.  When  we  speak  of  sanitary  surroundings  for  citizens,  what  do 
we  mean  ?  24.  What  power  has  the  board  of  health  in  most  cities  ? 
25.  What  good  conditions  and  what  bad  conditions  are  to  be  found 
in  your  own  town  ?  26.  Tell  what  you  can  about  pure-food  laws  and 
food  inspection.  27.  What  can  be  said  about  the  use  of  coal-tar  dyes 
in  foods?  28.  What  articles  of  food  have  a  standard  quality  set  for 
them  by  law  ?  29.  How  safe  are  patent  medicines  ? 


CHAPTER  XXI 


OUR  FOE  — THE  TUBERCLE  BACILLUS 

Ravages  of  Tuberculosis.  Perhaps  no  discovery  con- 
nected with  the  lungs  has  ever  interested  the  thinking 
people  of  the  world  quite  so  much  as  that  of  Dr.  Robert 
Koch  in  1882.  This  man  was  a  German  scientist,  and 
when  he  declared  that  he  had  found 
the  microbe  which  kills  more  human 
beings  each  year  than  any  other  one 
disease,  the  news  seemed  almost  too 
good  to  be  true. 

The  fact  is  that,  until  1882,  no  one 
knew  the  cause  of  tuberculosis,  or  how 

Three  thousand  put  end 

to  prevent  it.  Yet,  in  all  lands,  doctors  to  end  win  measure  one 
have  been  and  still  are  appalled  at  the 
death  rate  that  follows  wherever  the  disease  goes.  By 
studying  the  records  they  see  that,  each  year,  in  New 
York  City  alone,  10,000  men,  women,  and  children  die 
of  tuberculosis;  that,  in  the  United  States  as  a  whole, 
500,000  people  are  constantly  ill  with  it;  that  150,000 
of  this  number  die  each  year  of  tuberculosis ;  and  that 
in  the  world  at  large,  there  is  about  the  same  death  rate 

from  the  same  disease.     Moreover,  it  is  evident  that 

289 


TUBERCLE  BACILLI 


290       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

the  ranks  are  quickly  refilled  by  those  who  were  well, 
but  who  in  some  mysterious  way  have  been  stricken 
with  the  disease.  Doctors  also  realize  that  in  the  whole 
world  about  1,000,000  people  are  killed  by  tubercle  bacilli 
each  year. 

Dr.  Koch's  Discovery.  In  the  past  the  saddest  part  of 
the  situation  was  that  when  a  person  found  he  had 
tuberculosis  he  felt  helpless  about  it.  He  thought  the 
chances  were  all  against  his  getting  well  again.  He 
even  thought  there  was  little  to  do  but  to  get  ready  to 
die.  Imagine  then  the  great  hope  that  sprang  up  every- 
where when  Dr.  Koch  announced  that  he  knew  where 
tuberculosis  came  from  and  how  men  might  escape  it. 
He  said  he  had  made  the  discovery  by  the  use  of  his 
microscope,  and  that  what  he  found  was  a  living  and 
growing  thing.  He  gave  the  microbe  a  name  —  tubercle 
bacillus ;  studied  its  size  and  shape ;  noticed  its  habits ; 
watched  it  multiply;  learned  how  it  may  be  conquered 
in  the  human  body  and  also  saw  what  conditions  favor 
its  rapid  growth.  Knowing  as  he  did  that  each  one  of 
his  discoveries  would  help  save  the  lives  of  men,  he  pub- 
lished his  conclusions  promptly.  Here  are  a  few  of  his 
facts  stated  in  close  succession.- 

1.  Each  separate  bacillus  is  a  separate  plant. 

2.  Each  is  small  and  slender  like  a  tiny  rod. 

3.  Three    thousand   of  these   microbes   put   end 
to   end   will   measure   one   inch. 


OUR  FOE  — THE  TUBERCLE  BACILLUS  291 

4.  Each  multiplies  by  dividing. 

5.  The  only  place  where  they  can  multiply  is 
in  the  bodies  of  men  and  animals,  or  in  laboratories 
where  scientists  raise  them. 

6.  After  they  leave  the  body  they  live,  but  ap- 
parently they  cannot  multiply. 

7.  They  live  best  in  damp,  dark  places. 

8.  In  such  places  they  keep  alive  from  a  few 
weeks  to  two  years. 

9.  Bright  sunshine  kills  them  in  a  few  hours. 

10.  Boiling  kills  them  at  once. 

1 1.  Cold  does  them  no  harm. 

1 2.  They  can  live  and  float  about  in  the  driest  dust. 

13.  They  may  cause  tuberculosis  in  any  part  of 
the  body. 

14.  They  cause  it  in  the  lungs  most  often. 

15.  Tuberculosis   of   the   lungs  is  what  we  call 
consumption. 

The  discovery  of  all  these  facts,  one  by  one,  was  ex- 
citing to  every  doctor,  every  scientist,  and  every  con- 
sumptive who  heard  about  them ;  for  each  one  knew 
that  a  turning  point  had  come  in  the  history  of  the 
disease,  and  that  there  was  hope  now  for  thousands  of 
people  who  had  been  hopeless  before. 

It  was  also  clear  that  all  sorts  of  people  were  ex- 
posing others  to  the  disease  every  day,  and  that  each 
one  was  blameless,  for  until  Koch's  great  discovery  no 


292       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

one  knew  the  facts  about  the  tubercle  bacillus.  Now, 
however,  various  earnest  men  and  women  learned  these 
facts  and  studied  the  history  of  tuberculosis  both  in 
the  country  and  in  the  city. 

Records  from  "  Lung  Block. "    They  found  that,  as  a 
rule,  there  is  more  consumption  in  places  where  people 


116118120  122  124  126  128  130  132  134  136  138 138$  140  142  144  146  148  150  152  154  156  158  158 | 

Cherry  Street 

"  LUNG  BLOCK " 

The  shaded  parts  show  courts  and  air  shafts.    Each  letter  stands  for  one  case 
consumption  reported  since  1894.    All  the  "a's"  belong  to  1894,  the  "b's" 
1895,  the  "  c's"  to  l896'  etc->  UP  to  I9°3 


are  crowded  together  in  dark  rooms  than  anywhere  else, 
and  that  even  in  such  places  there  is  the  greatest  differ- 
ence in  special  houses  and  special  rooms.  This  was  the 
case  with  what  was  called  "  Lung  Block  "  in  New  York 
City.  From  these  houses,  during  nine  years,  two  hundred 
and  sixty-five  cases  were  reported  to  the  health  depart- 
ment, and  very  many  more  were  unreported.  Single 
rooms  also  told  their  sad  stories. 


OUR  FOE  — THE  TUBERCLE  BACILLUS  293 

Mr.  Ernest  Poole,  who  studied  the  subject  thoroughly, 
made  a  printed  report  of  one  of  these  rooms,  covering  a 
seven-year  period.  He  says  the  room  was  on  the  third 
floor,  looking  down  into  a  court,  and  that  in  it  people 
died  of  consumption  steadily,  one  after  the  other. 

1.  A  blind  Scotchman,  in  1894,  had  consumption, 
went  to  the  hospital,  and  died  there. 

2.  His  daughter  had  consumption  and  died. 

3.  One  year  later  a  Jew  was  taken  ill  there  and 
died  in  the  summer. 

4.  A  German  woman  took  the  disease  and  died. 

5.  An   Irishman  was  the  next  victim.     He  was 
weakened  by  overwork,  caught  the  disease,  fought 
against  it  bravely,  but  died  in  1901. 

East-Side  Conditions.  Another  house  on  the  East  Side 
of  the  city  had  dark  halls  where  one  needed  to  grope  his 
way  about,  seventy  small  rooms  with  almost  no  outside 
air  and  light,  and  an  air  shaft  partly  rilled  with  rubbish 
and  filth.  One  hundred  and  fifty  people  lived  in  that 
house  and  died  fast  of  consumption.  In  the  middle 
apartment  on  the  second  floor,  five  families  were 
lodged  one  after  the  other  for  four  years.  One  of  the 
first  family  died,  two  from  the  second,  and  one  from 
the  third,  while  two  members  of  the  fourth  family  died 
in  the  hospital  after  leaving  the  place. 

Surely,  the  saddest  part  of  such  a  record  as  this  is  the 
ignorance  of  the  victims  themselves.  When  they  first 


294        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

visit  the  house,  they  notice  nothing  more  objectionable 
than  darkness,  dirt,  and  close  air.  They  discover  no 
microbes,  suspect  nothing,  and  decide  to  come  to  the 
rooms  to  live.  They  do  not  know  that  the  chances  are 
that  some  of  them  have  come  to  those  rooms  not  to 
live  but  to  die. 

Now  how  does  it  happen  that,  over  and  over  again, 
in  every  crowded  city,  after  there  has  been  one  death 
from  consumption  in  a  house  other  cases  are  almost 
sure  to  follow,  and  then  still  others  again,  for  years 
and  years  afterwards  ? 

The  Tubercle  Bacillus  :  how  Lodged  and  Distributed. 
The  whole  explanation  is  in  the  nature  of  the  microbe, 
the  tubercle  bacillus  itself.  Those  who  examine  the  room 
can  of  course  see  no  sign  of  these  microbes,  yet  there 
may  be  millions  of  them  in  the  dust,  in  the  cracks  of  the 
floor,  on  the  walls  and  the  ceiling,  or  hidden  in  the  folds 
of  the  curtains.  Often  all  they  need  is  to  be  stirred  up 
by  a  broom  that  has  not  been  dampened  or  to  be  flour- 
ished about  with  a  feather  duster ;  for  in  either  way  they 
are  tossed  into  the  air  and  are  ready  to  do  their  mischief. 

Dry  dusting  is  bad.  It  simply  lifts  the  microbes 
from  the  spot  where  they  are  quiet  and  harmless  and 
scatters  them  in  the  air,  where  they  threaten  all  who 
breathe  it.  Damp  or  oily  dusters  are  best.  Wet  saw- 
dust or  torn-up  damp  .paper  scattered  on  the  floor  before 
sweeping  will  keep  the  microbes  from  being  scattered. 


OUR  FOE  — THE  TUBERCLE  BACILLUS  295 

After  microbes  once  reach  a  room,  they  will  live 
there  for  months  and  even  for  two  years  unless  the 
place  is  thoroughly  disinfected.  This  work  of  disinfect- 
ing a  room  or  a  house  is  so  important  and  needs  to  be 
done  so  thoroughly  that  in  almost  every  case  a  doctor 
or  a  city  official  must  attend  to  it. 

The  Nature  of  the  Microbe.  The  very  nature  of  the 
microbe  explains  all  this.  It  has  no  mind.  It  makes 
no  plans.  It  simply  lives  on  when  nothing  kills  it  and 
multiplies  when  it  finds  favorable  surroundings.  Yet  it 
never  goes  hunting  for  a  home,  for  it  cannot  move 
about  of  itself.  On  the  contrary,  if  it  is  in  the  air,  the 
wind  may  drive  it  anywhere,  and  it  will  stay  where  it  is 
tossed  until  something  starts  it  moving.  It  is  so  small 
that  a  man  may  breathe  it  with  the  air.  It  may  escape 
all  the  cilia  and  the  mucus  of  the  air  passages  and  safely 
reach  the  spot  where  it  grows  the  best,  the  lungs  of  a 
human  being. 

Bacilli  in  the  Lungs.  Here  everything  is  favorable. 
The  place  is  warm  and  moist,  the  delicate  tissue  is 
good  ground  to  grow  in,  and  the  microbe  begins  to 
multiply  promptly. 

Yet  there  is  another  side  to  the  situation.  The 
lungs  themselves  seem  to  make  a  protest.  They  like 
the  microbe  no  better  than  a  human  eye  likes  a  bit 
of  cinder.  At  once,  therefore,  certain  cells  of  the  lungs 
hurry  to  the  spot,  surround  the  microbe,  and  try  to 


296        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

build  themselves  into  a  wall  about  it.  In  a  way  it  is 
a  sort  of  contest,  and  at  last  the  multiplying  microbes 
and  the  cells  are  bunched  together  in  a  hard  lump 
called  a  tubercle. 

Sometimes  the  cells  of  the  lungs  are  vigorous  enough 
to  fasten  the  microbes  up  so  securely  that  they  can- 
not multiply.  In  this  case  they  become  harmless,  and 
the  man  does  not  have  consumption.  At  other  times 
the  microbes  prove  to  be  the  stronger.  The  tubercles 
then  increase,  the  man's  lungs  gradually  become  use- 
less, and  finally  he  dies. 

Danger  from  Sputum.  Always  the  peril  to  other  people 
is  from  what  a  tuberculous  person  coughs  up.  It  seems 
that,  as  each  tubercle  grows  larger,  the  center  of  it 
softens,  and  the  person  must  get  rid  of  it.  This  is  the 
sputum.  Often  it  has  a  yellow  color  and  is  full  of 
the  microbes  themselves.  The  worse  off  a  man  is,  the 
more  he  coughs  and  expectorates;  and  the  more  he 
expectorates,  the  more  of  the  living,  dangerous  microbes 
he  sends  into  the  outer  world. 

Those  who  know  about  it  say  that  a  man  with  con- 
sumption may  expectorate  two  or  three  billion  tubercle 
bacilli  every  twenty-four  hours. 

Tuberculosis  of  the  Bones.  Instead  of  tuberculosis  of 
the  lungs,  young  children  are  more  apt  to  have  tubercu- 
losis of  the  bones,  which  gives  them  crooked  backs  and 
hip  disease.  This  is  often  cured  by  skillful  doctors. 


OUR  FOE  — THE  TUBERCLE  BACILLUS  297 

Consumption  not  Inherited.  Fortunately,  however,  no 
one  inherits  any  kind  of  tuberculosis.  To  be  sure,  chil- 
dren of  consumptive  parents  often  have  it,  but  they  may 
have  every  chance  to  take  it  after  they  are  born ;  for  they 
may  live  in  the  same  house  with  their  careless,  consump- 
tive parents,  may  touch  the  same  things,  breathe  the 
same  microbe-laden  air  every  day,  and  may  even  creep 
about  on  the  floor,  where  dust  and  microbes  are  thickest. 
Worse  yet,  without  intending  the  slightest  harm,  those 
parents  may  even  kiss  their  children  on  the  lips.  They 
do  not  know  that  this  should  never  be  done. 

With  thousands  of  careless  people  coughing  and 
expectorating  every  day  for  months  and  for  years,  it  is 
easy  to  understand  how  streets  and  houses,  rooms  and 
people,  may  become  infected ;  for  each  new  case  of  a 
person  who  is  careless  with  his  sputum  means  more 
microbes  to  shift  about,  and  at  a  moment's  notice  they 
are  ready  to  go  back  into  the  lungs  of  any  human  being. 
After  that,  the  vigor  of  those  lungs  themselves  is  the 
only  thing  that  can  save  a  man.  This  explains  the  im- 
portance of  the  great  war  between  man  and  the  microbe 
which  is  now  being  waged. 

War  against  the  Enemy.  In  1907  the  Maryland  Asso- 
ciation for  the  Prevention  and  Relief  of  Tuberculosis 
had  an  exciting  campaign.  Its  rally  call  was,  "  Will 
you  help  build  the  fence  ? "  And  for  twenty-three 
days  this  mystic  query  appeared  in  large  letters  on  every 


WILL  YOU 

HELP 

BUILD    THE 
FENCE 


298        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

street  car  in  Baltimore  and  on  nearly  every  blank  wall ; 
even  the  ash  cans  did  not  escape.  At  first  there  was 
puzzled  curiosity  on  the  part  of  those  who  saw  the  sign ; 

next  came  interest;  and 
when  the  meaning  of  the 
question  was  discovered, 
when  all  knew  that  it  meant 
a  "  fence  "  of  prevention  to 
protect  people  against  consumption,  there  was  such 
enthusiasm  that  in  less  than  three  weeks  ten  thou- 
sand dollars  were  raised  for  the  use  of  the  association 
during  1907. 

This,  then,  is  the  sort  of  warfare  that  is  going  on  in 
Maryland  and  elsewhere  in  the  world  to-day.  Now  that 
we  have  actually  found  the  foe,  now  that  we  know  both 
how  to  kill  him  and  how  to  protect  ourselves  from  him, 
we  are  pledging  ourselves  to  do  it.  We  know  that  there 
are  just  two  ways  by  means  of  which  the  world  may 
banish  tuberculosis: 

1.  By  destroying  the  microbes   which    start    the 
disease. 

2.  By  making  human  bodies  vigorous  enough  to 
resist  the  microbes. 

In  conducting  this  campaign,  let  the  triple  motto  be: 

1.  Tuberculosis  is  preventable  ;  we  will  prevent  it. 

2.  Tuberculosis  spreads ;  we  will  check  it. 

3.  Tuberculosis  can  be  cured ;  we  will  cure  it. 


OUR  FOE  — THE  TUBERCLE  BACILLUS  299 

The  Anti-Tuberculosis  Crusade.  With  this  as  their 
motto  men  and  women  in  all  lands  are  now  carrying 
on  a  world-wide  anti-tuberculosis  crusade.  They  are 
printing  and  distributing  leaflets  by  the  hundred  thou- 
sand and  the  million,  for  they  are  determined  that  those 
who  are  well  shall  know  how  to  protect  themselves  from 
the  microbes  of  those  who  are  ill,  while  at  the  same 
time  those  who  are  ill  shall  know  enough  not  to  pass 
their  microbes  on  to  others. 

The  sad  fact  is  that  multitudes  of  people  are  ignorant 
both  about  giving  and  about  taking  the  disease.  Never- 
theless it  is  as  true  to-day  as  it  ever  was  that  the 
person  who  breathes  dust  loaded  with  tubercle  bacilli 
is  in  danger  of  tuberculosis,  and  that  the  only  way  to 
escape  the  danger  is  to  keep  the  lungs  healthy  and  not 
to  breathe  such  dust. 

Yet  how  shall  we  keep  from  doing  this  ? 

Careless  people  leave  their  deadly  sputum  in  crowded 
rooms,  cars,  theaters,  stations,  and  saloons.  It  then 
passes  through  all  the  stages  of  drying,  being  crushed, 
turning  to  powder,  and  getting  into  the  air;  and  after- 
wards, in  each  of  those  places,  people  must  breathe  the 
contaminated  air.  In  a  dusty  city  street  a  man  breathes 
anywhere  from  ten  to  four  hundred  microbes  a  minute, 
according  to  the  place  he  is  in;  and  the  larger  the 
number  the  greater  the  chance  that  tubercle  bacilli  are 
among  them. 


300       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Carelessness  in  Public  Places.  When,  therefore,  you  see 
a  man  expectorate  carelessly  on  street  or  floor,  you  have 
a  right  to  say  to  yourself :  "  One  thing  is  plain  —  either 
that  man  is  absolutely  ignorant  or  absolutely  selfish; 
either  he  does  not  know  the  laws  of  health,  the  habits 
of  the  microbe,  and  the  laws  of  the  city  against  spitting, 
or  he  is  willing  to  run  the  risk  of  giving  a  deadly 
disease  to  his  fellow  citizens." 

Of  course  it  is  true  that  saliva  without  tubercle  bacilli 
can  do  no  harm,  but  city  officials  know  that  what  the 
well  man  does  the  ill  man  is  sure  to  do.  For  this  reason 
laws  against  spitting  extend  to  everybody  —  young  and 
old,  well  or  ill  —  who  comes  where  they  are  in  force. 
Many  cities  post  their  laws  in  cars,  stations,  and  all 
public  places,  and  they  enforce  them  or  not  according 
to  their  zeal  for  the  welfare  of  their  citizens.  Here  is  a 
New  York  notice: 

Spitting  on  the  floor  of  this  car  is  a  misdemeanor.  A  fine  of  $500,  or 
imprisonment  for  one  year,  or  both,  may  be  the  punishment  therefor. 

Some  cities  are  so  much  in  earnest  about  this  matter 
that  men  in  tall  silk  hats  as  well  as  those  in  shabby 
derbies  have  been  fined  for  breaking  the  law. 

Public  Sentiment.  A  few  years  ago  very  few  people 
protested ;  few  even  noticed  the  spitting.  Now,  how- 
ever, the  man  who  spits  is  noticed  by  a  dozen  different 
people  at  once,  and  each  one  looks  upon  him  as  either 


OUR  FOE  — THE  TUBERCLE  BACILLUS  301 

a  deserter  from  the  camp  of  good  citizens  or  as  a  person 
ignorant  of  the  laws  of  health. 

Rules  of  Prevention.  For  his  own  sake,  therefore,  as 
well  as  for  the  sake  of  his  city,  each  loyal  citizen  should 
practice  the  following  rules  of  prevention: 

1.  Never  spit  in  a  place  where  sputum  may  dry 
and  get  into  the  air. 

2.  Use  paper  or  -cloth  and  burn  the  sputum  be- 
fore it  dries,  or  else  use  a  spittoon  that  has  water 
in  it  to  prevent  the  microbes  from  drying  and  float- 
ing around  in  the  air.    Clean  the  spittoon  often. 

3.  If  there  is  a  persistent  cough  and  a  good  deal 
of  sputum,  tell  the  doctor  about  it.    He  will  have 
the  sputum  examined. 

Every  doctor  in  the  land  knows  how  important  this 
last  point  is,  for  the  secret  of  curing  consumption  is  to 
discover  it  when  it  begins,  and  the  most  usual  way  to 
do  this  is  to  examine  the  sputum  for  tubercle  bacilli. 

Cure  for  Tuberculosis.  This  disease  is  really  somewhat 
like  a  fire  in  a  lumberyard.  If  the  fire  is  discovered 
when  it  starts,  a  single  pail  of  water  will  dash  it  out ;  but 
if  it  is  left  until  the  whole  lumberyard  is  blazing,  even 
the  fire  department  cannot  save  the  lumber.  So  too  with 
tuberculosis.  Three  quarters  of  the  cases  found  early 
and  taken  care  of  are  cured,  while  the  cure  itself  is  often 
as  simple  as  the  fire  cure,  although  in  the  case  of  con- 
sumption four  things  are  needed  instead  of  one. 


302        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

1.  Fresh  air  from  morning  until  night  and  from 
night  until  morning. 

2.  Sunshine. 

3.  Wholesome  food,  with  fresh  milk  and  eggs. 

4.  Rest  for  body  and  mind. 

If  the  patient  discovers  the  disease  soon  after  he  takes 
it,  and  if  he  can  get  those  four  things,  he  will  probably 
recover;  if  he  cannot  get  them,  he  will  probably  die. 

Safety  for  Others.  Consumptives  who  are  careful  about 
their  sputum  are  not  in  danger  of  giving  consumption  to 
others.  They  may  live  under  the  same  roof  with  them, 
work  side  by  side,  breathe  the  same  air  from  day  to  day, 
and  yet,  from  first  to  last,  if  they  destroy  every  drop  of 
their  sputum,  other  people  are  not  in  danger.  As  tuber- 
cle bacilli  never  fly  away  from  a  damp  surface  they  stay 
in  the  throat  and  air  tubes  of  a  consumptive  and  are  not 
expelled  in  his  breath  unless  he  breathes  hard  or  sneezes. 
If  he  does  either,  he  should  hold  a  cloth  before  his  mouth 
and  burn  it  immediately  or  have  it  boiled. 

Five    Tuberculosis  "  D's."     Any  person  with  a  vigor- 
ous body  is  best  able  to  resist  every  sort  of  disease  mi- 
crobe.  To  secure  such  a  body,  let  each  of  us  learn  to  shun 
what  have  been  called  the  five  tuberculosis  D's  —  dirt* 
darkness,  dampness,  dust,  and  drink.    Let  us  also  practice 
the  golden  rule  of  the  anti-tuberculosis  leagues: 
Dont  give  consumption  to  others. 
'  Dont  let  others  give  consumption  to  you. 


OUR  FOE  — THE  TUBERCLE  BACILLUS  303 

Those  who  understand  tuberculosis  best  speak  very 
positively  about  using  medicines  for  it.  They  say: 

1.  No  medicine  has  yet  been  found  that  will  cure 
consumption. 

2.  Advertised   medicines   often    contain    alcohol, 
which  hastens  consumption. 

3.  No  person  with  consumption  can  afford  to  run 
the  risk  of  taking  any  advertised  medicine. 

4.  In  taking  medicine,  a  consumptive  should  fol- 
low the  advice  of  a  good  doctor. 

Then  too,  from  first  to  last,  they  should  ever  seek 
those  four  best  things  —  fresh  air,  sunshine,  wholesome 
food,  and  rest 

Outdoor  Air.  In  the  country  as  well  as  in  the  city,  men 
need  to  know  both  how  to  prevent  tuberculosis  and  how 
to  cure  it  if  it  has  made  a  start.  Wise  people  will  see  to 
it  that  windows  are  open  in  their  homes,  their  shops,  and 
their  schoolhouses.  They  will  keep  them  open  by  night 
as  well  as  by  day,  for  they  will  know  that  less  dust  is 
being  stirred  up  at  night,  and  that  night  air  is  therefore 
the  best  air  to  be  had. 

At  the  same  time  they  will  make  sure  that  their  bodies 
are  warmly  covered  when  they  sleep  in  cold  rooms  full 
of  fresh  air.  An  inexpensive  way  to  get  extra  covering 
is  to  sew  newspapers  between  blankets.  Paper  does,  in 
fact,  keep  cold  out  so  well  that  in  some  places  paper 
blankets  are  manufactured,  and  they  can  be  bought  by 


304        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

the  dozen  at  a  very  low  cost.    Keeping  warm  enough  and 
breathing  fresh  air  must  go  hand  in  hand. 

In  a  city  even  hospitals  have  trouble  in  giving  a  man 
all  the  air  he  needs.  Windows  are  kept  open,  and  re- 
clining chairs  are  put  on  the  roof  for  certain  patients 
to  use.  Other  patients  breathe  fresh  air  even  in  bed, 


FRESH  AIR  ON  THE  ROOF  IN  A  CITY 

for  the  cot  itself,  with  the  patient,  is  thrust  through 
an  open  window  into  the  air  and  sunshine.  But  a  sana- 
torium or  a  tent  in  the  country  is  best  of  all  for  a  tuber- 
cular patient,  because  in  such  places  every  needed  thing 
is  at  hand. 

Some  consumptives  do  not  have  tents,  but  actually 
sleep  out  of  doors  in  midwinter. 


OUR  FOE  — THE  TUBERCLE  BACILLUS 


305 


Sleeping  Outdoors  in  Winter.  Professor  Irving  Fisher 
says  he  did  this  when  the  temperature  was  ten  degrees 
below  zero.  He  also  says  that  in  the  winter  of  1904, 
in  the  Adirondack  Cottage  Sanatorium,  six  people  slept 
outdoors  when  the  temperature  was  thirty  degrees  below 
zero.  They  had  two  or  three  mattresses  under  them, 
warm  blankets  and  comforters  over  them,  heavy  night 


FRESH  AIR  AND  SUNSHINE  TO  CURE  CONSUMPTION 

clothes  about  them,  and  also  woolen  headgear  with  an 
opening  for  the  nose. 

Each  person  knew  that  the  more  fresh  air  he  could 
get,  the  more  chance  he  had  to  live.  It  even  seemed  as 
if  the  colder  the  air  the  better  they  felt. 

Open-Air  Classes.  It  is  because  of  these  facts  that 
what  are  called  open-air  classes  are  springing  up  in 
many  places.  Those  who  start  the  classes  know  that 
every  chance  for  life  and  health  is  increased  for  children 


306       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

who  have  been  attacked  by  tubercle  bacilli  if  they  can 
do  their  studying  out  of  doors  and  not  within  the  four 
walls  of  a  schoolroom. 

In  this  great  anti-tuberculosis  war,  town  and  country 
people  are  sure  to  be  victorious  in  the  end,  but  how 
soon  the  end  will  come  depends  on  whether  or  not  the 
children  of  the  world  understand  how  serious  the  dan- 
ger is,  and  whether  or  not  they  are  willing  to  join  the 
forces  that  fight  tuberculosis  in  every  land. 

Let  us  all  remember  that  prevention  is  better  than 
cure,  and  that  fresh  air  is  as  important  to  keep  us  well 
as  to  help  cure  us  after  we  are  ill.  Let  us  make  sure  that 
fresh  air  gets  into  our  homes  by  day,  and  that  we  sleep 
in  abundance  of  it  by  night.  Let  us  do  what  we  can 
for  our  general  health  and  thus  help  save  ourselves  from 
the  foe  without  wings  that  comes  floating  to  us  in  the 
air  we  breathe.  And  what  of  that  other  foe  which  may 
reach  us  in  a  glass  of  clearest-looking  drinking-water? 
We  turn  now  to  typhoid  microbes  and  study  them  in 
their  natural  surroundings. 

QUESTIONS 

1.  What  was  Dr.  Koch's  great  discovery  in  1882  ?  2.  What  causes 
consumption?  3.  What  is  the  annual  death  rate  from  tuberculosis  in 
the  United  States  ?  in  the  world  ?  4.  In  past  times  what  has  been 
the  saddest  part  of  the  situation?  5.  How  did  Dr.  Koch's  discovery 
bring  hope  ?  6.  Is  each  separate  tubercle  bacillus  a  plant  or  an  animal  ? 
7.  Tell  of  its  shape,  size,  how  and  where  it  multiplies.  8.  How  many 


OUR  FOE  — THE  TUBERCLE  BACILLUS  307 

of  them  put  end  to  end  will  measure  one  inch  ?  9.  In  what  kind  of 
places  do  they  live  best?  10.  How  long  can  they  live?  11.  How 
does  bright  sunshine  affect  them  ?  intense  heat?  intense  cold?  12.  What 
becomes  of  them  in  the  driest  dust?  13.  To  what  parts  of  the  body 
can  tubercle  bacilli  give  tuberculosis  ?  to  which  part  most  often  ? 

14.  What  is  the  common  name  for  tuberculosis  of  the  lungs  ? 
15.  Where  is  most  consumption  found?  16.  Describe  "lung  block." 
17.  Mention  ways  in  which  one  case  of  consumption  leads  to  other 
cases.  18.  Describe  the  conditions  found  in  a  New  York  East-Side 
house.  19.  Where  do  microbes  stay  ?  20.  How  do  they  reach  the 
air  from  their  lodging  places?  21.  What  objection  is  there  to  dry 
sweeping  and  the  feather  duster  ?  22.  Wrhat  should  one  use  instead  ? 
23.  How  does  the  microbe  get  into  the  lungs  ?  24.  What  favorable 
conditions  does  it  find?  25.  In  what  way  do  the  lungs  seem  to  pro- 
test? 26.  Why  is  sputum  dangerous?  27.  How  many  tubercle  bacilli 
may  a  consumptive  person  expectorate  within  twenty-four  hours  ? 
28.  What  articles  may  hold  them  ?  29.  What  may  become  of  them 
afterwards?  30.  How  many  people  inherit  tuberculosis?  31.  How 
do  children  of  consumptive  parents  get  the  disease  ?  32.  So  far  as 
tubercle  bacilli  are  concerned,  what  especial  advantage  is  there  in 
having  vigorous  lungs? 

33.  Describe  the  anti-tuberculosis  war  in  Maryland  in  1907. 
34.  Mention  two  ways  by  means  of  which  the  world  may  banish 
tuberculosis.  35.  Give  the  triple  motto  of  the  campaign.  36.  Why 
do  we  make  laws  against  spitting  in  public  places  ?  37.  Give  the  New 
York  law.  38.  Why  do  we  compel  healthy  people,  as  well  as  those  who 
are  ill,  to  observe  the  law  ?  39.  W7hat  rules  of  prevention  should  every 
loyal  citizen  practice  ?  40.  In  what  way  is  tuberculosis  like  a  fire  in 
the  lumberyard  ?  41.  What  four  things  are  needed  to  cure  consump- 
tion? 42.  Mention  the  five  tuberculosis  "  D's."  43.  What  is  the  golden 
rule  of  the  anti-tuberculosis  leagues  ?  44.  What  can  you  say  about 
using  medicine  for  consumption  ?  45.  When  sleeping  in  cold,  fresh 
air,  what  must  be  done  about  keeping  warm  ?  46.  How  do  city  hospitals 
manage  to  give  their  patients  fresh  air  ? 


CHAPTER  XXII 

THE  CHOICE:  PURE  WATER  AND  CLEAN  MILK  OR 
TYPHOID  MICROBES  AND  TYPHOID  FEVER 

Former  Conditions  in  Pittsburgh.  Year  after  year,  for 
thirty-five  years,  people  died  in  Pittsburgh,  Pennsylvania, 
under  the  scourge  of  typhoid  fever.  As  the  city  grew, 
the  number  of  deaths  multiplied  until,  in  1907,  622 
people  died  of  typhoid  alone. 

But  the  misfortune  was  greater  than  this ;  for,  besides 
those  who  died,  there  were  thousands  of  other  people 
who  suffered  but  did  not  die.  Hundreds  at  a  time  were 
ill  in  their  homes  and  in  the  hospitals  of  the  city.  They 
lost  money  because  they  could  not  work  for  daily  wages. 
They  paid  out  for  doctors'  bills  and  medicine  savings 
that  were  intended  for  food,  fuel,  clothing,  and  house 
rent.  Thousands  of  children  were  hungry  and  cold  be- 
cause their  parents  were  too  ill  to  care  for  them  and  too 
weak  to  work.  It  is  indeed  estimated  that  for  each 
person  who  dies  of  typhoid  fever  eight  other  persons 
are  ill  with  it. 

Explanation  of  the  Death  Rate.  So  matters  progressed 
from  bad  to  worse  for  thirty-five  years.  In  the  meantime 

a  generation  of  people  came  and  went.   And  what  was 

308 


WATER,  MILK,  AND  TYPHOID  FEVER  309 

the  explanation  of  this  death  rate?  Just  one  thing.  The 
drinking-water  of  Pittsburgh.  Why,  then,  did  the  citizens 
use  it?  Because  at  that  time  multitudes  of  people  did 
not  know  the  facts  about  pure  and  impure  drinking- 
water.  They  did  not  know  that  every  case  of  typhoid 
fever  is  started  by  a  small  living  thing  which  comes 
from  the  body  of  some  one  who  has  the  fever.  They  did 
not  know  that  this  microbe  is  harmless  unless  it  gets 
into  our  mouths  and  we  swallow  it  alive.  They  did  not 
know  that  their  own  drinking-water  was  loaded  with 
living,  active  typhoid  microbes  which  had  come  direct 
from  the  bodies  of  other  people.  They  did  not  even 
know  that  boiling  kills  disease  microbes,  and  that  any 
boiled  water,  no  matter  how  wretched  it  looks,  is  safe  to 
drink  because  it  is  free  from  living  typhoid  microbes. 

And  just  because  they  were  ignorant,  multitudes  of 
honest,  hard-working  people  in  Pittsburgh ,  took  city 
water  as  it  came  from  the  faucet  and  drank  it  without 
fear. 

How  Typhoid  Microbes  reached  Pittsburgh.  Perhaps 
we  wonder  why  this  particular  water  was  so  full  of  the 
microbes.  Any  map  of  that  section  of  the  country  helps 
us  to  find  the  explanation.  Notice  the  location  of  Pitts- 
burgh. See  how  it  lies  at  the  point  where  the  Allegheny 
and  Monongahela  rivers  join  to  form  the  Ohio.  Follow 
the  two  streams  upward  and  notice  that  all  the  way 
along  towns  and  cities  are  ranged  on  both  banks  of  both 


!  U. 


310        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

streams.  There  are  over  seventy-five  of  these  groups  of 
houses,  and  their  united  population  gives  a  total  of  over 
350,000  human  beings.  This,  then,  throws  light  on  the 
entire  water  problem  of  Pittsburgh,  for  it  turns  out  that 

each  of  these  towns  and  cities 
pours  all  its  waste  water,  its 
sewage,  into  the  river  on  w7hose 
banks  it  stands.  A  most  natural 
riddance  of  it  surely,  for  the 
river  carries  off  the  waste,  taking 
it  downstream.  But  think  of  the 
next  step  in  this  water  history. 

Not  only  does  each  town  empty 
all  its  sewage  into  the  river,  but 
each  town  also  takes  all  its  drink- 
ing-water from  the  same  river. 
In  other  words,  the  sewage  of 
each  town  becomes  part  of  the 
drinking-water  of  all  the  towns 
that  lie  farther  downstream. 
Naturally  the  mixture  grows  con- 
stantly worse,  and  by  the  time 
it  reaches  Pittsburgh  it  is  fearful  stuff  to  drink. 

Nevertheless,  just  as  it  was,  without  any  pretense  at 
killing  the  microbes  or  taking  them  out,  this  liquid 
compound  of  water,  waste,  and  filth  was  in  those  days 
turned  'directly  into  the  huge  water  pipes  of  Pittsburgh, 


TOWNS   THAT   CONTAMINATE 

DRINKING-WATER 


WATER,  MILK,  AND  TYPHOID  FEVER  311 

and  the  masses  of  the  people  drank  it  with  no  suspicion 
of  danger.  Had  they  known  the  peril  and  the  way  of 
escape,  they  would  have  saved  themselves. 

Microbes  and  Drinking- Water.  We  ourselves  know  that 
if  there  are  no  typhoid  microbes  in  our  drinking-water, 
however  wretched  its  color  and  taste  may  be,  it  cannot 
by  any  possibility  give  us  typhoid  fever.  We  also  know 
that  however  clear  and  sparkling  it  may  be,  if  there  are 
typhoid  microbes  in  it,  disease  and  death  may  go  to  the 
one  W7ho  drinks  it.  In  the  case  of  Pittsburgh,  many 
persons  upstream  had  typhoid  fever,  and  their  sewage, 
with  its  load  of  microbes,  was  poured  into  the  stream 
and  sent  from  city  to  city  as  the  stream  rolled  onward. 
Pittsburgh  suffered  most  simply  because  it  was  farthest 
downstream  and  had  therefore  received  more  sewage  in 
its  drinking-water  than  any  other  place. 

Safety  through  Sand  Filters.  Then  came  an  abrupt, 
astonishing  change  in  the  death  record.  During  the 
single  month  of  October,  1907,  596  persons  had  been  ill 
with  the  fever.  But  during  the  month  of  October,  1908, 
there  were  but  96  cases  of  it  in  the  city ;  and  deaths  for 
the  entire  year  dropped  off  in  like  proportion.  This 
changed  record  has  continued  to  the  present  day.  And 
the  explanation  of  the  entire  change  rests  with  the  sand 
filters  which  were  set  to  work  in  1908.  These  filters  are 
near  the  city,  46  in  number,  and  worth  visiting.  Each 
covers  an  acre  of  ground;  each  is  about  five  feet  deep; 


312        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

each  is  a  separate  bed  of  pebbles,  gravel,  and  fine  sand 
—  pebbles  on  the  bottom,  sand  on  top.  River  water 
is  turned  on  these  filters.  It  soaks  through  slowly  and 
is  carried  in  water  pipes  to  the  homes  of  Pittsburgh. 
Nothing  could  be  more  unpretentious  and  matter  of  fact 

than  those  huge  sand  filters.1  Yet 
they  are  the  life-saving  stations  of 
the  city.  They  purify  the  water 
and,  by  so  doing,  save  hundreds  of 
lives  each  year.  Scores  and  scores 
of  towns  and  cities  are  saving 
themselves  by  the  same  sensible 
method.  At  the  same  time,  multi- 
tudes of  other  townspeople  are 
drinking  unsafe  water.  Most  of 
them  do  this  ignorantly. 

Now  think  for  a  moment  of  the 
water    conditions    in    your    town. 

From  coarse  gravel  to  fine       -|Tn  ,  i    •    i  • 

San5  Where  does   your   drinking-water 

come  from?    If  from  a  river,  study 

some  map  and  try  to  decide  whether  or  not  other  people 
farther  upstream  are  sending  their  sewage  down  to  you. 

1  Multitudes  of  microbes  live  and  multiply  on  the  surface  of  large,  out-of-door 
filters.  They  find  their  best  food  in  the  worst  kind  of  water  and  sewage.  When 
water  is  poured  upon  a  filter  bed,  these  hungry  microbes  take  the  impurities  out, 
and  also  destroy  disease  microbes  —  and  other  kinds  too  —  that  were  in  it.  After 
this,  the  water  is  safe  to  drink.  Thus  it  is  that  microbes  on  the  sand  purify  our 
water  for  us,  and  save  us  from  disease  microbes. 


SAND  FILTER 


WATER,  MILK,  AND  TYPHOID  FEVER  313 

If  so,  when  typhoid  fever  attacks  any  person  in  that 
town,  you  yourself  will  be  in  danger.  Clearly  enough, 
then,  all  river  water  that  is  exposed  to  human  contami- 
nation should  be  either  boiled  or  sent  through  outdoor 
sand  filters  before  it  is  used  as  a  drink.  A  small  filter 
in  the  house  does  not  purify  water  in  the  same  way. 
It  takes  out  dust  and  color,  but  it  does  not  remove 
disease  microbes. 

Lake  Water  for  Drinking.  Perhaps  your  drinking- 
water  comes  from  a  lake.  If  no  human  beings  send 
sewage  of  any  sort  into  that  lake,  water  from  it  may 
be  used  fearlessly  as  a  drink.  Generally,  however,  large 
lakes  receive  much  sewage  from  houses  and  towns  that 
stand  on  their  shores.  For  safety's  sake,  then,  such  lake 
water  should  be  either  boiled  or  filtered. 

Danger  from  Well  Water.  Perhaps  you  draw  water 
from  a  cool  country  well  and  feel  very  safe  as  you  drink 
it.  Still  there  may  be  danger  even  here.  For  example, 
two  friends  enjoyed  what  they  considered  delicious 
water  from  a  country  well  in  northern  Ohio.  One  month 
later  both  men  were  down  with  typhoid  fever  and  one 
of  them  died.  What  was  the  trouble  ?  Those  who 
examined  the  surroundings  afterwards  saw  that  the  well 
was  too  near  the  dwelling  house  to  make  it  safe.  Water 
from  the  surface  of  the  ground  found  its  way  into  the 
well,  and  with  it  had  gone  sewage  from  a  man  who  had 
had  typhoid  fever  in  the  house.  The  water  itself  was 


314        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

cool  and  clear  as  crystal.  Neither  by  its  taste,  its  color, 
nor  its  odor  did  it  tell  any  tales  about  itself.  Dangerous 
microbes  were,  however,  concealed  in  it.  This  peril  from 
well  water  is  so  real  that  many  a  village  which  depends 


DRINKING-WATER  FROM  A  WELL 

Notice  that  both  well  and  cesspool  are  near  the  house.  The  contents  of  the  cess- 
pool soak  through  the  ground  without  hindrance  and  contaminate  the  water  which 
supplies  the  well.  If  typhoid  microbes  are  in  the  cesspool,  they  will  get  into  the 

drinking-water 

(From  The  Human  Mechanism,  by  Hough  and  Sedgwick) 

on  wells  is  more  in  danger  from  typhoid  fever  than  are 
large  cities  which  supply  themselves  with  water  brought 
to  town  through  pipes  from  some  pure  though  distant 
source. 

Sources   of   City  Water.     Judging  by  the  facts,  then, 
it    begins    to    look    as    if   water  were    encompassed    by 


WATER,  MILK,  AND  TYPHOID  FEVER  315 

danger.  So  it  is  wherever  sewage  from  man  can  in 
any  wise  reach  it.  For  this  reason  we  have  all  grown 
more  careful  about  the  sources  of  our  water  supply. 
Some  cities  draw  it  from  mountain  springs  and  from 
small  lakes  which  cannot  be  contaminated  by  man. 
Others  build  huge  reservoirs  and  protect  them.  Here 
water  is  stored  by  the  hundred  million  gallons  at  a 
time.  Still  other  places  yet  filter  such  water  as  they  are 
obliged  to  use  from  undesirable  sources.  For  example, 
London,  in  England,  must  use  water  from  the  Thames. 
Yet,  as  this  river  flows  by,  it  carries  sewage  from 
many  towns  on  its  way  to  the  sea.  Nevertheless  even 
the  terrible  water  of  the  Thames  is  so  purified  by 
sand  filters  that  London  is  remarkably  free  from 
typhoid  fever. 

It  is  unpleasant  to  use  unclean  drinking-water,  but  as 
already  shown,  the  real  danger  to  life  is  from  the  disease 
microbes  which  may  be  in  it.  They  may  give  typhoid 
fever  and  other  intestinal  troubles.  As  a  safeguard 
against  typhoid  fever,  doctors  now  inoculate  people  and 
thus  protect  them. 

Rain  Water.  It  is  raining  at  the  present  moment, 
and  I  think  of  the  pure  water  that  comes  from  the 
skies.  Not  a  microbe  is  in  it,  for  microbes  never 
ascend  to  the  clouds  when  water  evaporates.  Float- 
ing microbes  may  be  in  the  air  on  a  dusty  day,  but 
these  are  washed  out  by  the  first  dash  of  raindrops. 


316       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Everywhere  in  the  world,  therefore,  rain  water,  direct 
from  the  sky,  is  safe  to  drink.  And  when  this  water  is 
caught  in  clean  tanks  and  kept  away  from  all  human  con- 
tamination, it  continues  to  be  the  safest  water  we  have. 

In  deciding  whether  to  live  in  this  town  or  that,  always 
make  some  inquiry  about  the  water  supply  before  you 
come  to  any  decision  as  to  where  to  make  your  home. 
For  life  itself  depends  on  the  purity  of  drinking-water. 

Typhoid  Epidemic  from  Milk.  Then,  too,  there  is  that 
other  important  drink — the  milk  we  use  so  constantly. 
Even  in  this  there  may  be  danger  from  harmful 
microbes.  In  Springfield,  Massachusetts,  in  1882,  typhoid 
fever  suddenly  appeared  in  several  different  homes  at 
about  the  same  time.  On  investigation  it  was  found 
that  all  who  had  the  fever  took  milk  from  the  same 
milkman,  and  a  little  later  it  also  appeared  that  a  man 
had  just  had  typhoid  fever  in  the  milkman's  home. 
Just  how  the  microbes  reached  the  milk  no  one  could 
say.  Perhaps  the  milk  cans  were  washed  in  contami- 
nated water.  Perhaps  typhoid  microbes  were  on  the 
hands  of  the  man  who  did  the  milking.  However  it 
was  done,  there  was  no  doubt  about  the  fact.  In  one 
way  or  another  typhoid  microbes  had  reached  the  milk 
and  passed  the  disease  on.  Scarlet  fever  and  other 
diseases  have  sometimes  been  carried  in  the  same 
way.  But  it  is  typhoid  microbes  that  threaten  milk 
most  'frequently. 


WATER,  MILK,  AND  TYPHOID  FEVER  317 

Conditions  of  Clean  Milk.  In  the  town  where  I  live 
there  is  just  now  quite  a  rivalry  in  the  milk  business. 
Two  men  are  trying  to  outdo  each  other  in  the  per- 
fection of  the  milk  they  deliver.  On  one  neat-looking 


A  MODEL  DAIRY 
Clean  cows,  clean  stables,  and  clean  milk 

milk  wagon  the  printed  sign  reads,  "Clean  Milk 
Dairy " ;  on  the  other  there  are  but  two  words,  "  Pure 
Milk."  As  for  ourselves  who  buy  the  milk,  we  know 
that  from  both  wagons  the  best  of  milk  is  delivered  to 
us.  We  are  sure  of  this  because  both  dairies  believe  in 
cleanliness,  and  try  to  secure  it.  They  know  that  the 


318        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

cleaner  the  milk  the  fewer  the  microbes,  the  fresher  the 
milk  the  fewer  the  microbes,  the  colder  the  milk  the  fewer 
the  microbes. 

In  both  dairies,  therefore,  clean  cows  are  kept  in 
clean  stables ;  they  are  milked  by  clean  men,  who 
wash  their  hands  before  they  do  the  milking.  Clean 
pails,  clean  pans  and  bottles,  all  are  kept  fresh  and 
sweet  through  the  use  of  boiling  water  and  "live 
steam."  Those  who  conduct  this  business  know  that 
microbes  multiply  faster  in  warm,  unclean  milk  than 
elsewhere,  and  that  each  speck  of  mud,  each  bit  of 
horsehair,  that  enters  the  milk  carries  countless  mi- 
crobes with  it.  They  also  know  that  each  of  these 
microbes  begins  to  multiply  at  once  and  that  no 
amount  of  straining  can  take  out  microbes  after  they 
are  once  in  a  liquid.  These  men  are  therefore  wise 
enough  to  be  careful  of  the  milk  supply  from  the 
time  it  is  drawn  until  it  is  delivered.  In  addition, 
they  keep  it  cool  from  start  to  finish. 

Unclean  Milk.  It  is  quite  otherwise,  however,  with 
certain  men  who  carry  on  the  same  important  business 
in  a  neighboring  town.  They  do  not  seem  to  know  that 
dirt  and  microbes  go  together,  that  the  more  dirt  the 
more  microbes,  that  the  older  the  milk  the  more  microbes, 
that  the  warmer  the  milk  (before  it  is  cooked}  the  more 
microbes  of  many  kinds  will  be  in  it.  As  a  result  their 
milk  is  not  such  as  we  should  wish  to  use. 


WATER,  MILK,  AND  TYPHOID  FEVER 


319 


Boiling  Milk  to  kill  Microbes.  If  at  any  time  you  are 
not  sure  about  the  history  of  your  milk  supply,  and  if 
you  wish  to  make  it  perfectly  safe,  remember  the  old 


CLEAN  MILK  FOR  ROCHESTER  BABIES 

lesson   that  boiling  kills    microbes  wherever   they  are. 
Two  things  may  render  milk  harmful: 

1.  The  presence  of  disease  microbes  which  may 
reach  it  through  carelessness. 

2.  The  presence  of  too  great  a  number  of  mi- 
crobes which  are  harmless  in  themselves. 


320       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Pure  Milk  for  Babies.  For  young  babies  this  last 
danger  is  the  real  one.  Various  cities  are  beginning  to 
take  this  fact  into  account  and  are  trying  to  supply  the 
babies  of  the  city  with  milk  which  carries  as  few  mi- 
crobes as  possible  and  no  danger  whatever.  By  means 
of  pure  milk  the  city  of  Rochester,  New  York,  reduced 
the  death  rate  of  its  babies  from  1000  in  1892  to  less 
than  500  in  1904.  Thus  one  example  is  added  to  another 
and,  the  world  over,  fathers  and  mothers  are  learning 
that  the  kind  of  milk  they  buy  helps  decide  what  the 
death  rate  of  their  youngest  children  shall  be.  It  is 
indeed  the  children  who.  suffer  most  through  the  igno- 
rance of  their  elders.  The  next  chapter  proves  this. 


QUESTIONS 

••**•'••*•,  '.. 
£'  What  special  disease  became  a  scourge  in  Pittsburgh?    2.  How 

many  died  of  typhoid  fever  in  1907  ?  3.  How  did  other  people  suffer 
from-  the  disease  even  when  they  did  not  die?  4.  How  long  did  the 
scourge  last?  5.  What  caused  it?  6.  How  could  it  have  been  pre- 
vented? 7.  Why  was  it  not  prevented?  8.  Tell  what  you  can  about 
the  typhoid  microbe  itself.  9.  How  does  it  get  into  the  body  ?  10.  What 
do  towns  on  the  banks  of  the  Allegheny  and  Monongahela  rivers  do 
with  their  sewage?  11.  Where  does  their  drinking-water  come  from? 
12.  Why  was  Pittsburgh  water  worst  of  all  ?  13.  What  one  thing  is  it 
that  makes  water  unfit  to  drink?  14.  Describe  the  change  that  came 
in  the  Pittsburgh  death  rate  in  1908.  15.  What  explained  the  change? 
16.  Describe  the  Pittsburgh  sand  filters.  17.  What  do  they  do  to  water  ? 
18.  Where  does  your  own  drinking-water  come  from  ?  19.  Why  is  river 
water  generally  unsafe  to  drink  ?  20.  Why  is  water  from  a  lake  unsafe  ? 


WATER,  MILK,  AND  TYPHOID  FEVER  321 

21.  When  is  well  water  unsafe?  22.  How  can  sewage  get  into  a 
well?  23.  What  do  cities  do  for  water?  24.  Tell  about  London  water. 
25.  Why  is  rain  water  safe  to  drink  ? 

26.  Describe  the  typhoid  epidemic  in  Springfield.  27.  Describe  the 
difference  between  clean  milk  and  unclean  milk.  28.  How  do  microbes 
get  into  milk  ?  29.  Why  should  milk  be  clean,  fresh,  and  cold  ?  30.  In 
what  sort  of  milk  do  microbes  multiply  fastest?  31.  How  can  unclean 
and  unsafe  milk  be  made  safe  to  use  ?  32.  Mention  two  ways  in  which 
harm  may  come  through  microbes  in  the  milk. 


CHAPTER  XXIII 

CAUSE  AND  PREVENTION,  OR  SAFETY  FROM  MICROBE 

DISEASES 

Preventable  Diseases.  In  every  country  and  in  all 
parts  of  the  world,  men,  women,  and  children  are  asked 
to  join  the  modern  army  and  help  wage  the  modern 
war  against  the  following  preventable  diseases :  tubercu- 
losis, typhoid  fever,  measles,  smallpox,  scarlet  fever,  hy- 
drophobia, whooping  cough,  pink  eye,  trachoma,  malaria, 
yellow  fever,  pneumonia,  the  hookworm  disease,  and  our 
everyday  colds. 

As  we  study  the  list  let  us  bear  in  mind  three  facts: 

1.  Disease  microbes  are  killing  more  human  be- 
ings each  year  than  are  being  killed  in  any  other 
way. 

2.  Those  who  die  of  any  disease  are  few  in  com- 
parison to  those  who  suffer  from  it. 

3.  If  we  were  all  careful  enough  about  preven- 
tion, our  preventable  diseases  would  soon  be  wiped 
out  of  existence.   Think  of  the  difference  this  would 
make  in  the  happiness  and  the  welfare  of  the  world. 
Yet   carelessness  often  comes   through   ignorance. 

.Take  the  following  case  for  example:     . 

322 


SAFETY  FROM  MICROBE  DISEASES  323 

Measles  and  Scarlet  Fever.  A  boy  in  New  York  City 
who  thought  he  had  measles1  went  to  bed,  called  the 
doctor,  stayed  at  home  for  some  time,  then  was  well 
again  and  went  back  to  school.  After  that  he  became 
very  popular.  Why?  Because,  as  Mr.  Riis  says,  "He 


CITY  OF  BOSTON.— HEALTH  DEPARTMENT 

NOTICE 


OF    A    CASE    OF 


Scarlet  Fever. 

When  the  danger  from  infection  has  Passed  this 
card  will  be  removed. 


Any  Person  removing  this  card  without  authority 
is  liable  to  a  fine  of  One  Hundred  Dollars. 


PLACED  ON  A  HOUSE  BY  THE  BOARD  OF  HEALTH 

could  pull  the  skin  off  with  his  fingers  as  one  would 
skin  a  cat."  And  he  gave  the  largest  rolls  to  his  dearest 
friends.  He  did  not  know  and  his  friends  did  not  know 
that  disease  microbes  are  thick  in  each  smallest  frag- 
ment of  skin  that  comes  from  any  one  who  has  had 

1  Mr.  Riis,  who  tells  the  story,  says  the  boy  had  the  measles.  But  critics  think 
the  disease  must  have  been  scarlet  fever,  because  the  peeling  and  the  danger 
from  the  skin  is  much  greater  after  scarlet  fever  than  after  measles. 


324        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

measles  or  scarlet  fever.  So  the  skin  went  from  the 
boy  to  his  friends.  They  took  it  home  with  them  and 
divided  it  among  their  other  friends. 

Then  came  the  climax.  A  great  spreading  epidemic 
broke  out  wherever  the  skin  had  been  distributed. 
Many  were  ill ;  some  died ;  all  suffered.  If  those  boys, 
their  parents,  and  their  friends  had  known  the  facts 
about  measles,  they  would  have  used  their  brains  and 
saved  their  bodies  from  a  very  preventable  epidemic. 

Here  are  a  few  of  these  facts :  Both  measles  and  scar- 
let fever  are  known  as  eruptive  diseases  because  they 
cause  eruption  of  the  skin.  After  this  the  dead  skin 
peels  off  in  bits.  The  victim  should  not  mix  with  other 
people  until  the  so-called  "  peeling "  is  well  over,  for 
those  harmless-looking  bits  of  dead  skin  may  be  alive 
with  danger,  and  nothing  but  isolation  of  the  patient 
can  keep  him  from  scattering  disease.  It  is  necessary 
to  take  special  care  of  the  eyes  while  recovering  from 
either  scarlet  fever  or  measles. 

Smallpox.  There  is  another  contagious  disease  which 
is  far  more  terrible  than  measles.  In  the  year  1854  this 
disease  broke  out  on  Ponape,  one  of  the  Micronesian 
islands.  It  came  from  the  garments  of  a  sailor  who 
had  died  there  of  smallpox.  At  the  time  of  his  death 
Ponape  had  a  population  of  ten  thousand;  but  six 
months  later  half  of  those  ignorant  islanders  were  dead 
and  buried.  The  microbe  of  smallpox  had  slain  them 


SAFETY  FROM  MICROBE  DISEASES  325 

before  they  had  had  time  to  learn  how  to  protect  them- 
selves from  this  preventable  disease. 

In  former  times  people  dreaded  smallpox  and  fled 
from  it.  They  knew  it  was  contagious  and  realized  what 
its  results  were ;  but  they  tried  in  vain  to  escape  it. 
Though  they  fled,  they  were  overtaken  by  it;  they  suf- 
fered from  it  and  carried  the  marks  of  it  on  their  faces 
until  they  died.  They  were  also  killed  by  it  by  the  hun- 
dred thousand  every  year.  According  to  a  careful  calcu- 
lation, fifty  million  Europeans  died  of  smallpox  between 
the  years  1700  and  1800. 

Then  at  last  an  Englishman,  Dr.  Jenner,  learned  how 
to  save  men  by  vaccination.  Since  that  time  smallpox 
has  slipped  into  the  background  of  the  deadly  diseases 
of  the  world.  The  explanation  is  that  to-day  in  every 
civilized  country  vaccination  has  been  adopted  as  a  pre- 
ventive. It  is  true  that  nowadays  people  feel  so  safe  that 
they  often  grow  careless.  Even  the  mothers  of  the  chil- 
dren sometimes  forget  to  have  their  sons  and  daughters 
vaccinated.  In  such  cases,  however,  the  board  of  health 
of  the  city  or  town  often  steps  in  and  gives  commands. 
This  was  done  by  New  York  City  in  1901.  Without 
much  warning  smallpox  had  appeared  in  the  place.  Peo- 
ple here  and  there  who  had  not  been  vaccinated  were 
down  with  the  fever  and  were  dying.  Two  hundred 
special  inspectors  were  appointed  at  once,  and  within 
six  months  eight  hundred  and  ten  thousand  people, 


326        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

young  and  old,  had  been  vaccinated,  and  the  city  was 
saved  from  what  would  have  been  an  epidemic  more 
frightful  than  that  which  swept  over  Ponape.  For  in  a 
city  human  beings  are  crowded  so  close  together  that 
microbes  have  a  chance  to  spread  fast.  Vaccination  is, 
however,  such  a  sure  road  of  escape  that  certain  cities 
compel  all  the  children  to  be  vaccinated  before  they  let 
them  go  to  school. 

Diphtheria.  Here,  also,  we  have  a  swift-moving  disease 
which  seems  to  fly  from  house  to  house  through  the 
power  of  an  unseen  foe.  We  ourselves  know  that  in  this 
case  too  the  invisible  power  is  a  microbe,  which  takes 
its  start  within  the  throat  and  is  able  to  kill  its  victim. 

As  it  happens  in  any  attack  of  diphtheria,  life  de- 
pends on  the  speed  with  which  prevention  can  overtake 
the  microbe  as  it  multiplies.  A  child  has  a  sore  throat, 
then  a  fever.  The  doctor  is  called,  and  if  he  finds  all  the 
signs  of  the  dread  disease,  he  knows  that  his  one  hope  is 
to  kill  the  microbes  before  they  can  kill  the  child.  With- 
out a  moment's  delay,  therefore,  he  uses  the  one  great 
cure  for  diphtheria  —  antitoxin.  He  not  only  puts  this 
into  the  body  of  the  child  who  is  ill,  but  also  gives  it 
to  each  person  who  has  been  anywhere  near  the  child. 
Indeed  the  infection  itself  passes  so  swiftly  from  one  to 
another  that  the  only  safety  is  to  use  antitoxin  on  all 
alike.  It  not  only  helps  cure  the  one  who  has  the  dis- 
ease, but  also  protects  those  who  have  been  exposed  to 


SAFETY  FROM  MICROBE  DISEASES  327 

it.  In  previous  times  about  forty  of  every  hundred  who 
had  diphtheria  died  of  it.  Now  it  kills  not  more  than 
eight  in  each  hundred.  The  difference  in  the  death  rate 
is  explained  by  the  power  of  antitoxin  to  save  those  who 
have  been  attacked  by  the  microbe. 

Hydrophobia.  In  still  another  terrible  disease,  antitoxin 
of  another  sort  plays  an  important  part. 

Not  long  ago  the  newspapers  reported  the  sad  case  of 
three  persons  who  had  been  bitten  by  a  mad  dog  in  a 
country  town.  He  had  been  a  good-natured  dog,  and  no 
one  suspected  danger  until  he  had  bitten  one  boy  and 
two  men.  He  was  then  caught  and  mercifully  killed. 
And  what  of  the  men  and  the  boy?  The  doctors  in  the 
place  knew  that  there  was  hope  of  life  for  them  if  they 
could  be  treated  with  an  antitoxin  prepared  for  just  such 
cases,  for  it  destroys  the  power  of  hydrophobia  microbes 
after  they  have  been  put  into  the  body  by  the  teeth  of  a 
mad  dog.  All  three  of  the  victims  were  therefore  hurried 
to  Chicago.  There  they  were  treated  at  a  special  hos- 
pital for  such  cases.  One  man  had  been  a  little  slow 
in  arriving,  and  he  alone  suffered  from  the  disease.  The 
other  man  and  the  boy  were  saved  by  the  antitoxin, 
which  was  given  in  time.  Perhaps  no  suffering  is  more 
dreadful  and  no  death  much  sadder  than  that  which 
comes  through  hydrophobia.  But  in  these  days  this  dis- 
ease is  preventable,  for  large  cities  in  all  parts  of  the  civi- 
lized world  prepare  antitoxin  and  supply  it  to  the  doctors 


328        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

when  needed.  This  method  of  cure  was  one  of  the  great 
discoveries  of  Louis  Pasteur,  the  French  scientist. 

Dogs  are  not  the  only  living  creatures  that  put  mi- 
crobes into  man  by  cutting  through  his  skin.  Turn  to 
the  havoc  which  mosquitoes  have  wrought. 

Yellow  Fever  and  Malaria.  In  1793,  within  the  space 
of  six  and  a  half  weeks,  one  tenth  of  the  population  of 

Philadelphia  died  of  yellow  fever. 
Naturally,  of  course,  the  city  was 
in  a  panic.  No  one  knew  what 
started  the  fever  nor  how  it  trav- 
eled from  one  person  to  another. 
But,  thanks  to  science  once  again, 
we  now  know  that  if  every  mos- 
quito of  a  certain  kind  were  ban- 
STEGOMYIA  MOSQUITO  THAT  ished  from  the  earth  to-day,  no 

CARRIES  YELLOW  FEVER        ,  ,     .  ,  ,  .      -, 

human  being  would  ever  again  be 

killed  by  yellow  fever.  It  has  been  proved  that  stego- 
myia  mosquitoes  are  the  only  yellow-fever  agents  in  the 
world.  By  their  sting,  provided  they  themselves  have 
already  stung  a  yellow-fever  patient,  they  pass  the  disease 
along.  Malaria  is  another  disease  whose  contagion  is  car- 
ried by  mosquitoes  alone.  A  person  who  was  never  stung 
by  the  anopheles  mosquito  would  never  have  malaria. 
But  that  same  anopheles  must  first  sting  a  malarial  fever 
patient  before  he  himself  will  have  the  microbes  to 
pass  along.  Other  kinds  of  mosquitoes  do  us  no  harm 


SAFETY  FROM  MICROBE  DISEASES 


329 


whatever,  but  all  kinds  look  so  much  alike  that  our  path 
of  duty  is  plain.  We  must  therefore  try  to  keep  from  be- 
ing stung  by  any  kind  of  mosquito.  In  order  to  banish 
them,  we  must  prevent  their  eggs  from  hatching,  must 
get  rid  of  standing  water  where  eggs  may  be  laid,  and 
must  destroy  all  mosquito  wrigglers.  Many  cities  are 
doing  these  things.  Small 
ponds  and  marshy  places 
are  drained  or  filled  with 
earth.  Barrels  and  tanks 
holding  water  are  closely 
covered.  Cans,  bottles,  and 
discarded  kettles  which 
might  hold  water  after  a 
rainstorm  are  not  left  where 
mosquitoes  can  reach  them. 
Kerosene  oil  is  poured  over 
ponds  containing  eggs  and 
wrigglers.  This  oil  suffocates  the  wrigglers  before  they 
have  time  to  turn  themselves  into  full-fledged  mosquitoes. 
The  Hookworm  Disease.  So  much  for  our  flying  foe, 
but  what  shall  we  say  of  the  hookworm,  that  other  foe 
that  creeps  and  crawls,  and  bores  its  way  into  the  skin  ? 
In  this  case  our  objection  is  to  the  creature  itself  and 
not  to  any  microbes  which  he  may  put  into  us.  Fortu- 
nately for  mankind,  a  modern  discovery  shows  how  even 
hookworm  disease  may  be  prevented  and  cured. 


MOSQUITOES 

Above  is  anopheles  that  carries  malaria. 
Below  is  culex,  the  common,  harmless 
mosquito.  We  know  which  is  which  by 
the  position  each  takes  when  resting 


330       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

The  worms  themselves  get  into  the  body  in  two  ways : 

1.  Through  the  skin.    They  work  their  way  into 
bare  feet  that  tread  upon  them ;   they  prick  their 
way  into  the  hands  of  those  who  handle  them. 

2.  Through  the  mouth  on  things  that  are  eaten 
or  in  water  that  is  swallowed. 

When  they  enter  the  body  they  are  so  young  and  so 
small  that  they  cannot  be  seen  except  by  the  help  of  a 
microscope. 

After  they  are  in  the  body  they  travel  hither  and 
thither  in  the  blood  stream  until  they  reach  the  long 
tube  of  the  digestive  canal.  They  like  the  small  intes- 
tine best,  and  here  it  is  that  they  earn  their  name,  for 
they  hook  themselves  to  the  lining  of  the  tube  with  their 
mouths,  suck  up  blood,  even  eat  the  lining  itself,  and 
finally  grow  to  full  size  —  half  an  inch  long  and  as  large 
round  as  No.  8  cotton  thread.  As  many  as  three  thou- 
sand of  these  have  been  found  in  one  person. 

When  they  are  really  full-grown  they  lay  their  eggs 
by  the  thousand.  But  these  eggs  never  hatch  within 
the  human  body  where  they  were  laid.  Instead,  they 
are  sent  out  of  the  body  with  the  other  refuse,  and  the 
hatching  is  done  in  the  outside  world. 

Later,  when  the  young  hookworms  are  partly  grown 
(although  still  of  microscopic  size),  they  enter  any  human 
skin  within  reach.  If  they  do  not  get  the  chance  to  do 
this,  they  are  bound  to  die  without  descendants,  for 


SAFETY  FROM  MICROBE  DISEASES  331 

hookworms  never  lay  eggs  anywhere  except  in  the 
bodies  of  living  human  beings. 

The  real  objection  to  having  hookworms  within  us  is 
that  they  suck  up  so  much  blood  for  their  own  use  that 
the  owner  of  the  blood  suffers  for  lack  of  it.  When  this 
happens  we  say  that  he  has  hookworm  disease. 

Children  suffer  most.  During  the  time  that  hook- 
worms are  robbing  them  of  their  blood  they  grow  at 
a  snail's  pace  and  are  languid,  listless,  and  poorly 
developed.  They  have  what  are  called  pulsating  blood 
vessels  in  the  neck,  and  a  tallowlike  skin.  Hook- 
worms cause  it  all.  Indeed  hookworm  disease  affects 
nerves,  muscles,  lungs,  blood  and  circulation,  stomach 
and  digestion. 

When  the  worms  are  outside  the  body  they  thrive  best 
in  warm,  moist,  sandy  soil.  Naturally,  therefore,  the  dis- 
ease is  more  common  in  summer  than  in  winter  and  far 
more  prevalent  in  warm  regions  of  the  earth  than  in 
places  that  are  sometimes  wintry  cold. 

Very  often  hookworm  disease  starts  with  what  is 
called  ground-itch.  In  fact,  the  spot  that  itches  is  gen- 
erally nothing  but  the  place  where  the  worm  pierced 
the  skin  and  entered  the  body.  Sad  to  say,  in  parts 
of  the  earth  that  are  constantly  moist  and  warm  there 
are  to-day  thousands  of  men,  women,  and  children  who 
are  victims  of  this  hookworm  disease.  But  doctors  can 
cure  the  disease  and  prevent  its  return. 


332       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

1.  They  give  one  kind  of  medicine  to  kill  the 
worms  within  the  body. 

2.  They  give  another  kind  of  medicine  to  help 
the  body  drive  dead  hookworms  out  of  it. 

3.  They  see  to  it  that  refuse  which  passes  from 
the  human  body  is  put  where  no  worms  hatching 
out  from  the  eggs  that  may  have  been  in  it  can 
ever  get  into  the  neighborhood  of  human  beings. 

4.  They  teach  people  not  to  go  barefoot ;  not  to 
wear  leaky  shoes ;  not  to  put  the  hands  into  soil  that 
may  hold  hookworms ;  and  not  to  drink  water  that 
could  have  been   reached  by  hookworms. 

In  doing  all  these  things,  scientists  are  keeping  in 
mind  two  facts: 

1.  To    prevent    hookworm    disease,    hookworms 
and  human  beings  must  be  kept  apart. 

2.  The  way  to  keep   them   apart   is  to  prevent 
human   refuse  from   reaching  any  soil  which   may 
be  walked  upon,  and  from  reaching  any  water  that 
may  be  used  for  drinking. 

To  secure  these  results,  houses  must  be  connected 
with  a  sewer  system  that  carries  all  human  waste  to 
some  distant  point.  When  this  is  impossible,  houses 
—  whether  private  homes  or  schoolhouses  —  must  each 
have  what  is  known  as  a  sanitary  outhouse.  In  other 
words,  the  one  important  point  is  to  keep  the  ground 
free  from  human  pollution.  And  the  one  danger  from 


SAFETY  FROM  MICROBE  DISEASES  333 

this  pollution  is  that  it  may  have  hookworm  eggs  in  it 
by  the  hundred  and  the  hundred  thousand. 

Rules  for  those  living  in  Hookworm  Regions.  The 
following  medical  commands  must  be  obeyed  by  all 
who  live  in  hookworm  regions : 

1.  Stop  soil  pollution. 

2.  Build  and  use  sanitary  outhouses. 

3.  Never    go    barefoot    unless    the    ground    is 
perfectly  dry.     To   state   it   the   other  way  round : 
always  wear  shoes  when   it    is    raining,  when    the 
ground  is  wet,  even  when  dew  is  on  the  ground. 

Going  barefooted  on  wet  ground  in  hookworm  re- 
gions gives  hookworms  their  chance  to  enter  the  body. 

4.  If  you  get  ground-itch,  go  to  the  doctor  about 
it  at  once.    Always  take  treatment  for  hookworm 
disease   within   three    months  after  you  have  had 
an    attack   of   ground-itch. 

Whooping  Cough  and  Mumps.  From  such  an  unpleas- 
ant subject  as  hookworm  disease,  it  may  be  a  relief  to 
turn  to  whooping  cough  and  mumps.  Here  again  we 
have  two  diseases  that  reach  us  through  the  air.  While 
you  have  either  trouble,  stay  by  yourself  or  with  others 
who  suffer  similarly.  Do  not  mix  with  well  people  until 
the  doctor  allows  it.  Never  forget  that  when  you  cough 
you  throw  impurities  into  the  air,  and  that  those  who 
breathe  the  air  afterwards  will  draw  these  impurities  into 
their  lungs.  He  who  has  whooping  cough  or  mumps 


334       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

should  use  his  own  particular  knife,  fork,  spoon,  cup,  and 
tumbler  until  he  is  altogether  well  —  unless,  indeed,  he 
boils  them  all  after  using  them.  Boiling  will  make  them 
safe  for  others  to  use.  Perhaps  the  worst  thing  about 
whooping  cough  is  that  those  who  have  it  are  more 
easily  overcome  by  other  diseases  afterwards. 

Pneumonia.  The  same  is  true  of  that  dread  disease 
pneumonia.  The  word  itself  frightens  those  who  know 
most  about  the  disease.  They  tell  us  that  pneumonia  kills 
more  people  each  year  than  any  other  single  disease  ex- 
cept tuberculosis.  It  takes  young  and  old  alike.  Here, 
as  in  consumption,  the  microbes  multiply  with  extraor- 
dinary speed.  And  while  they  multiply  they  produce  a 
poison  which  is  deadly  enough  to  kill  the  strongest  man. 
The  microbe  of  this  disease  gets  into  the  air  from  the 
lungs  of  any  one  who  has  pneumonia.  Those  who  have 
it  must  therefore  stay  in  quarantine  until  they  are  welL 
At  the  same  time,  whatever  comes  from  the  mouth  must 
be  destroyed  as  carefully  as  if  the  disease  were  tubercu- 
losis. Pneumonia  usually  starts  when  one  has  a  cold,  or 
is  overtired,  or  has  spent  time  in  badly  ventilated, 
crowded  rooms.  It  also  comes  easily  after  some  other 
disease  that  has  left  the  body  weakened.  In  order  to 
escape  pneumonia,  then,  and  also  to  escape  every  other 
disease,  the  great  line  of  defense  is  to  keep  the  body  in 
vigorous  condition.  The  way  to  do  this  is  to  be  faithful 
in  following  the  general  laws  of  health. 


SAFETY  FROM  MICROBE  DISEASES  335 

Pink  Eye  and  Trachoma.  In  the  schoolroom,  however, 
even  very  healthy  children  may  have  pink  eye  or 
trachoma  if  they  are  careless  about  the  microbes  of 
these  diseases. 

The  former  is  a  nuisance ;  the  latter  is  a  very  serious 
eye  disease.  Both  afflictions  often  travel  by  the  road  of 
the  public  towel.  If  any  child  in  a  public  school  has  a 
contagious  eye  trouble  and  uses  the  school  towel,  he 
will  leave  his  eye-disease  microbes  on  it.  Later  these 
same  microbes  will  be  left  on  the  eyes  of  other  children 
who  use  this  towel.  When  an  epidemic  of  eye  disease 
is  actually  started,  do  not  touch  your  hands  to  your 
eyes.  Microbes  may  have  been  left  on  books,  pencils, 
and  desks  by  persons  who  have  touched  their  diseased 
eyes  with  their  hands.  By  handling  the  same  things 
you  may  take  the  same  disease  unless  you  are  strictly 
careful  to  keep  your  hands  away  from  your  eyes.  All 
this  restates  facts  given  in  Chapter  XIX. 

Disinfection  and  Antiseptics.  We  should  also  know 
that  after  any  contagious  disease,  the  room  or  the  house 
should  be  thoroughly  disinfected.  This  means  that  all 
the  microbes  of  the  special  disease  must  be  killed  in 
order  to  save  human  beings  from  infection.  The  doctor 
or  some  other  experienced  person  should  attend  to  this 
matter,  for  the  disinfection  of  a  house  is  not  the  simple 
affair  which  some  people  imagine  it  to  be.  Unless  it  is 
thoroughly  done,  it  is  useless. 


336        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

As  a  rule,  antiseptics  are  used  to  destroy  microbes 
on  the  body.  A  disinfectant  is  stronger  and  is  used  not 
on  the  body  but  on  clothes,  rugs,  etc.,  where  microbes 
must  be  killed. 

In  addition  to  all  else,  let  us  never  forget  that  the 
health  of  the  body  demands  two  great  things  of  us: 

1.  That  we   destroy   disease   microbes    (tubercle 
bacilli,  typhoid  microbes,  and  all  the  others)  before 
they  have  any  chance  to  attack  the  body. 

2.  That  we  keep  the  defenses  of  the  body  in  such 
vigorous  condition  that   even  if   disease  microbes 
enter,  they  will   not  conquer  us,  but  will  be  con- 
quered by  us. 

In  other  words,  our  war  against  the  microbe  means 
that  we  should  do  two  things,  and  that  we  should  do 
them  both  at  the  same  time: 

1.  Fortify  the  body. 

2.  Exterminate  the  foe. 

QUESTIONS 

1.  Mention  some  diseases  which  the  modern  army  fights.  2.  If 
everybody  were  careful,  what  would  happen  to  our  preventable  diseases  ? 
3.  What  danger  was  there  in  the  skin  the  schoolboy  distributed  ?  4.  How 
long  should  the  victim  of  an  eruptive  disease  —  measles,  etc.  —  stay  away 
from  other  people  ?  5 .  Describe  the  smallpox  epidemic  on  Ponape. 
6.  What  did  smallpox  do  in  Europe  between  1700  and  1800?  7.  What 
was  Dr.  Jenner's  discovery  in  1796  ?  8.  What  keeps  us  safe  from  small- 
pox nowadays?  9.  Describe  vaccination  in  New  York  City  in  1901. 
10.  Why  do  epidemics  spread  fastest  in  crowded  places?  11.  Where  in 


SAFETY  FROM  MICROBE  DISEASES  337 

the  body  does  diphtheria  start?  12.  In  diphtheria,  what  must  be  done 
at  once?  13.  Why  is  there  haste?  14.  To  whom  is  antitoxin  given? 
Why  ?  15.  What  was  the  former  death  rate  from  diphtheria  ?  the  death 
rate  now?  16.  What  should  be  done  for  a  person  who  has  been  bitten 
by  a  mad  dog?  17.  Why  is  delay  dangerous  ?  18.  What  epidemic  swept 
Philadelphia  in  1793  ? 

19.  What  causes  yellow  fever?  20.  How  may  it  be  banished  from 
the  earth?  21.  To  pass  the  disease  on,  what  must  the  stegomyia 
mosquito  first  do?  22.  Name  another  disease  carried  by  mosquitoes. 
23.  Which  mosquito  carries  malaria?  24.  How  does  the  anopheles 
mosquito  get  the  microbes  which  it  carries?  25.  Why  must  we  protect 
ourselves  from  the  sting  of  the  mosquito  ?  26.  What  are  cities  doing 
in  this  line?  27.  Why  do  they  pour  kerosene  oil  over  stagnant  ponds? 
28.  How  do  hookworms  enter  the  body?  29.  Where  in  it  do  they 
start?  30.  How  do  they  travel  about?  31.  Describe  their  feeding; 
their  size.  32.  Where  do  they  lay  eggs  ?  33.  W'here  do  the  eggs 
hatch?  34.  In  what  ways  do  people  surfer  from  hookworms  ?  35.  When 
outside  the  body,  where  do  they  thrive  best  ?  36.  Is  hookworm  disease 
more  common  in  summer  or  in  winter?  37.  In  what  regions  is  it  most 
often  found?  38.  What  is  ground-itch  a  sign  of?  39.  What  should 
be  done  with  human  waste  to  avoid  spreading  hookworm  disease  ? 
40.  Give  medical  commands  to  be  obeyed  wherever  hookworms  are 
found. 

41.  How  do  whooping  cough  and  mumps  reach  us  ?  42.  What  is  said 
about  knife,  fork,  spoon,  etc.  ?  43.  Why  is  pneumonia  such  a  serious  dis- 
ease ?  44.  Whom  does  it  attack,  the  young  or  the  old  ?  45.  How  fast  do 
pneumonia  microbes  multiply  ?  46.  What  do  they  produce  ?  47.  How  do 
they  get  into  the  air  ?  48.  How  should  the  patient  protect  the  air  from 
contamination  ?  49.  What  is  the  great  defense  against  pneumonia  and 
every  other  disease  ?  50.  Which  eye  diseases  may  be  caught  in  the 
schoolhouse?  51.  Why  should  we  shun  the  public  towel?  52.  How 
may  we  save  ourselves  from  eye  disease  ?  53.  Who  should  attend  to 
the  work  of  disinfection  ?  54.  What  two  great  things  does  the  health  of 
the  body  demand  of  us  ? 


CHAPTER  XXIV 

MAN'S  FRIEND  AND  DEFENDER  — THE  PHAGOCYTE 

Cholera  Microbes  and  the  Phagocyte.  Scientists  have 
known  for  a  long  time  that  the  red  blood  corpuscle  is 
the  oxygen  carrier  of  the  body,  but  for  years  they  came 
to  no  final  conclusion  about  the  occupation  of  his  busy 
companion  the  white  blood  corpuscle,  the  phagocyte l  — 
"  the  devourer,"  as  his  name  means  in  Greek.  The 
mystery  vanished,  however,  when  Professor  Metchnikoff, 
of  the  Pasteur  Institute,  in  Paris,  turned  his  attention 
to  the  subject. 

He  took  a  healthy  frog,  carefully  pricked  some  cholera 
microbes  under  its  skin,  and  with  his  microscope  watched 
the  fate  which  befell  them.  The  whole  affair  was  easy 
to  follow,  for  as  soon  as  the  cholera  microbes  entered 
the  blood  stream,  white  phagocytes  flocked  to  the  spot 
from  all  sides ;  they  crowded  close ;  each  seemed  to 
choose  its  special  victim,  and  drawing  closer  yet,  laid 
itself  alongside  its  enemy,  stretched  itself  into  a  new, 
curved  shape,  and  little  by  little  wrapped  itself  about 
the  doomed  microbe. 

1  All  phagocytes  are  white  blood  corpuscles,  but  there  are  also  white  blood 
corpuscles  that  are  not  phagocytes. 

338 


MAN'S  FRIEND  AND  DEFENDER 


339 


How  the  Phagocyte  captures  Microbes.  The  phagocyte 
is  really  nothing  more  than  a  tiny  round  speck  of  living, 
active,  independent  substance  called  protoplasm,  but  it 
captures  its  victims  relentlessly.  In  vain  the  microbes 
seemed  to  try  to  flee ;  their  captors  had  surrounded 
them  completely  and  held  them  firmly  within  their  own 
bodies  long  enough  to  digest  them.  Instead  of  killing 
an  enemy  outright  and  throwing 
him  aside,  they  rid  themselves  of 
him  by  swallowing  him  whole. 
Quickly  hurrying  to  another,  each 
phagocyte  repeated  the  process, 
disposing  of  one  microbe  after 
another  and  growing  larger  with 
each  captive. 

When  the  intruding  microbes 
were  small  enough  to  make  it  pos- 
sible, Professor  MetchnikofT  saw 
the  phagocyte  "  swallow  them  in 

shoals  as  a  whale  swallows  herring."  Whereas  if  they 
were  too  large  for  one  to  manage  alone,  several  phag- 
ocytes would  surround  the  same  microbe  and  digest 
him  in  partnership. 

In  this  connection  it  is  interesting  to  know  that  a 
frog  never  dies  of  cholera.  The  reason  is  clear  —  frog 
phagocytes  are  so  vigorous  that  they  conquer  cholera 
microbes  before  the  latter  have  a  chance  to  manufacture 


SHAPES  WHICH  ONE  PHAGO- 
CYTE  TOOK    WITHIN    A    FEW 

SECONDS 


340       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

their  deadly  toxin  and  give  cholera  to  the  frogs.  In  the 
same  line  of  investigation  Professor  Metchnikoff  next 
discovered  that  pigeons  cannot  be  made  to  take  tuber- 
culosis, for  here  again,  when  he  introduced  tubercle 
bacilli  into  a  pigeon's  blood,  the  phagocytes  seized 
them  as  fast  as  they  entered  the  body  and  devoured 
them  before  any  harm  was  done. 

The  work  which  the  phagocyte  does  for  the  body  is 
so  valuable  that  we  are  easily  tempted  to  talk  about  this 
free-swimming  single  cell  as  if  it  were  a  soldier  fighting 
our  battles.  In  point  of  fact,  however,  and  even  though 
they  do  behave  like  friend  and  foe,  there  would  seem  to 
be  no  real  enmity  between  the  phagocyte  and  the  microbe. 

How  Phagocytes  Travel.  These  small  protectors  of  the 
body  move  from  place  to  place  in  independent  fashion. 
They  spend  most  of  their  time  in  the  blood,  and  in 
it  they  not  only  travel  with  the  current  but  they  also 
ignore  the  current  entirely  and,  like  the  salmon,  swim 
upstream  as  well  as  downstream,  as  occasion  may 
require.  At  a  moment's  notice,  also,  they  can  leave 
the  blood  and  pass  through  any  bodily  tissue  without 
the  slightest  difficulty. 

Vigorous  and  Feeble  Phagocytes.  Through  Professor 
MetchnikofFs  experiments,  and  others  since  then,  facts 
have  been  learned  which  help  human  beings.  If  our 
phagocytes  are  strong  enough  to  destroy  disease  mi- 
crobes for  us,  we  shall  be  saved  from  certain  serious 


MAN'S  FRIEND  AND  DEFENDER 


341 


diseases.  If,  on  the  contrary,  our  phagocytes  are  feeble, 
or  if  microbes  enter  our  body  in  such  swarms  that 
there  are  not  phagocytes  enough  to  fight  them  suc- 
cessfully, the  enemy  will  be  victorious,  the  phagocytes 
will  be  defeated,  and  we  shall  be  the  victims  of  any 
disease  microbes  that  may  attack  us.  Put  two  men 


t  -• 


»v% 


,-%*  fl-s   ,    /       f '- 


INFLUENZA  MICROBES 

On  the  left,  as  they  are  found  in  the  sputum  of  some  colds ;  on  the  right, 
as  they  are  raised  in  the  laboratory 


into  a  town  where  cholera  is  working  havoc;  let 
one  have  more  vigorous  phagocytes  than  the  other, 
and  he  will  be  the  one  more  likely  to  escape  with 
his  life.  Let  measles  or  pink  eye,  whooping  cough 
or  influenza,  break  out  in  school,  and  those  children 
with  the  most  numerous  and  active  phagocytes  will 
suffer  the  least.  Let  tubercle  bacilli  be  thick  in  the 


342        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

dust  we  breathe,  and  those  of  us  who  own  the  best 
bodyguard  of  well-developed  phagocytes  will  be  least 
likely  to  take  the  disease  and  to  surfer  from  tuber- 
culosis afterwards. 

The  same  law  holds  true  even  for  less  serious  illness. 
When  some  one  says,  "  I  am  so  sensitive,  I  catch  cold 
at  the  least  exposure,"  it  is  quite  as  if  he  said,  "  My 
phagocytes  are  wonderfully  weak  and  inefficient;  they 
are  vanquished  by  all  the  microbes  of  influenza  that 
enter  my  body."  Another  person  says,  "  I  never  seem 
to  take  cold,"  and  it  is  as  if  he  said,  "  My  phagocytes 
are  such  valiant  warriors  that  they  destroy  every 
intruding  microbe." 

The  Phagocyte  as  a  Scavenger.  Yet  the  phagocyte  is 
not  merely  an  athletic  policeman  and  a  valiant  soldier; 
he  is  also  a  scavenger  and  a  street  cleaner  that  never 
seems  to  be  idle.  Here  and  there  through  the  body 
he  hurries,  always  trying  to  remove  waste  matter  and 
to  destroy  intruding  microbes. 

You  cut  your  hand,  or  you  run  a  sliver  into  your 
finger,  and  from  every  side  phagocytes  hasten  to  clear 
away  the  rubbish  and  to  attack  the  microbes.  If  they 
can  kill  these  mischief-makers  as  fast  as  they  drift  in, 
the  wound  will  heal  quickly ;  if,  instead,  the  phagocyte  is 
too  weak  to  slay  the  enemy,  there  will  be  a  painful  sore, 
slow  to  heal.  Hospitals  are  full  of  patients  who  prove 
this  difference  in  their  own  bodies.  One  man  has  a 


MAN'S  FRIEND  AND  DEFENDER  343 

wound  that  heals  at  once,  and  he  goes  home  happy; 
another  man  stays  in  the  hospital  for  weeks,  waiting 
for  his  wound  to  heal.  The  difference  in  the  time  of 
recovery  rests  with  the  phagocytes  of  the  two  men. 

What  Pus  Is.  Matter,  or  pus,  from  a  wound  is  the 
host  of  microbes  and  phagocytes  that  have  been  slain 
in  the  struggle.  They  are  being  washed  away  by  fluids 
from  the  wound.  It  has  been  estimated  that  in  one 
ounce  of  pus  there  may  be  as  many  as  150,000,000 
phagocytes  who  died  fighting. 

The  warfare  within  our  bodies  is  a  silent  one;  we 
hear  no  sound  of  any  conflict.  Nevertheless,  throughout 
our  lives  the  strife  goes  on  ceaselessly,  and  it  makes 
all  the  difference  between  life  and  death  to  us  whether 
or  not  our  standing  army  of  phagocytes  is  in  good 
fighting  trim. 

In  view  of  this  fact  our  daily  command  to  ourselves 
should  be :  Protect  the  phagocytes  from  harm.  Many 
laws  of  health  are,  indeed,  so  truly  laws  for  their  protec- 
tion that  he  who  follows  these  laws  most  strictly  will  at 
the  same  time  be  doing  the  most  for  his  bodyguard. 

Cholera  Epidemic  and  Alcohol.  In  Glasgow,  in  1848, 
a  little  more  knowledge  might  have  saved  hundreds  of 
lives.  A  great  cholera  epidemic  swept  through  the  city, 
and  it  attracted  so  much  attention  that  Dr.  Adams 
studied  it  for  the  sake  of  telling  people  how  to  pro- 
tect themselves.  He  kept  a  keen  eye  on  the  death 


344       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

rate  of  his  cholera  patients  and  discovered  that  those 
who  went  without  alcohol  had  a  vastly  better  chance  of 
recovery  than  those  who  used  it.  Or,  to  put  the  facts 
more  exactly,  when  those  who  used  alcohol  caught  the 
disease,  ninety-one  out  of  every  hundred  died ;  whereas, 
when  those  who  did  not  use  alcohol  had  the  cholera, 
only  nineteen  out  of  every  hundred  died. 

Knowing  what  we  do  about  the  effect  of  alcohol  on 
living  tissue,  and  knowing  also  about  the  discoveries 
which  Professor  Metchnikoff  made  in  connection  with 
cholera  microbes  and  phagocytes,  we  understand  at 
once  why  that  condition  of  affairs  existed  in  Glasgow. 
The  men  and  women  who  did  not  use  alcohol  owned 
phagocytes  that  were  vigorous  enough  to  conquer  the 
attacking  cholera  microbes;  the  men  and  women  who 
used  alcohol  had  weakened  their  phagocytes  to  such  an 
extent  that  when  invading  enemies  came  they  were  not 
strong  enough  to  slay  them. 

Dr.  Delearde  had  two  cases  which  illustrate  precisely 
this  point. 

Hydrophobia  and  Alcohol.  A  man  and  a  boy  were 
bitten  on  the  same  day  by  the  same  mad  dog.  The  boy, 
thirteen  years  old,  was  bitten  on  the  head  and  face, 
which  are  the  very  worst  places  for  such  wounds.  The 
man  was  bitten  on  the  hand  alone  —  a  much  less  serious 
matter.  Both  victims  were  taken  to  Dr.  Delearde,  and 
he  gave  each  his  most  careful  treatment;  but  the  man, 


MAN'S  FRIEND  AND  DEFENDER  345 

who  should  have  recovered,  died  of  hydrophobia,  and 
the  boy,  who  might  have  been  expected  to  'die,  recovered. 
The  only  difference  in  the  two  cases  seemed  to  be  that 
the  man  used  alcohol  and  the  boy  did  not. 

Alcohol  and  the  Phagocyte.  This  led  Dr.  Delearde  to 
make  experiments  to  determine  whether  or  not  alcohol 
had  any  effect  on  the  phagocytes.  He  took  two  sets  of 
rabbits ;  to  one  set  he  gave  a  little  alcohol  each  day ;  the 
other  set  received  no  alcohol.  He  then  vaccinated  both 
sets  as  a  protection  against  hydrophobia.  After  they  were 
supposed  to  be  proof  against  the  disease,  he  put  the 
poison  of  hydrophobia  into  their  blood,  and  the  experi- 
ment gave  the  result  he  had  expected.  The  rabbits  that 
had  had  alcohol  took  the  disease  as  easily  as  if  they  had 
not  been  protected  against  it,  whereas  the  poison  had 
no  effect  whatever  on  the  rabbits  that  had  not  had  alco- 
hol. They  did  not  take  hydrophobia.  Evidently  their 
phagocytes  had  served  them  well. 

In  looking  back  to  the  seventeenth  chapter  of  Health 
and  Safety,  we  now  understand  one  reason  why  Bum  and 
Tipsy  suffered  so  much  more  than  Nig  and  Topsy  when 
the  epidemic  of  dog  illness  raged  in  Worcester.  Alcohol 
had  weakened  their  phagocytes  to  such  an  extent  that 
disease  microbes  had  the  upper  hand  from  the  start. 

Just  here  it  is  necessary  to  call  attention  to  an  impor- 
tant fact.  When  death  comes  from  disease  microbes, 
it  is  not  the  microbe  itself  but  the  poison  which  the 


346        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

microbe  gives  off  while  it  multiplies  that  does  the  mis- 
chief. Each  disease  microbe  has  its  own  special  variety 
of  poison  (toxin),  and  fevers  of  one  sort  or  another 
simply  show  that  a  fierce  fight  is  going  on  between 
microbes  that  are  producing  poison  and  phagocytes  that 
are  devouring  the  poison  producers. 

Over  and  over  again,  in  many  microbe  diseases,  death 
comes  from  the  fact  that  the  body  is  poisoned  by  the 
toxin  which  the  microbes  have  produced. 

Phagocytes  that  Multiply  for  Emergencies.  This  is  par- 
ticularly true  in  that  dread  disease,  pneumonia,  and 
sometimes  a  doctor  helps  science  by  following  the  record 
of  the  battle.  From  time  to  time  he  draws  a  drop  of 
blood  from  the  arm  of  his  patient  and  examines  it  under 
the  microscope  for  phagocytes.  He  knows  that  the  suf- 
ferer's chance  of  life  increases  or  decreases  with  the 
number  of  these  protectors.  The  normal  count  is  from 
5000  to  7000  phagocytes  in  each  cubic  millimeter,  and 
it  takes  50  cubic  millimeters  to  make  one  drop  of 
water. 

When,  by  his  examination  of  the  blood,  the  doctor 
finds  that  the  number  of  phagocytes  is  mounting  steadily 
upward  from  10,000  to  20,000,  from  20,000  to  50,000, 
and  even  to  70,000,  he  takes  courage.  He  knows  that 
"  the  body  is  rallying  its  forces  to  battle  with  the  invad- 
ing hosts  of  microbes,  and  that  if  the  fight  can  be  kept 
up  long,  enough,  the  victory  will  be  won." 


MAN'S  FRIEND  AND  DEFENDER  347 

Scientists  say  that  phagocytes  are  being  manufac- 
tured constantly  in  certain  lymph  tissues,  and  that  when 
a  special  need  comes,  when  a  wound  is  made  in  the  flesh 
or-when  disease  microbes  multiply  in  the  blood,  then  the 
tissues  send  out  new  regiments  of  phagocyte  soldiers  by 
the  thousand  and  the  million.  And  it  seems  that  even 
the  youngest  of  these  soldiers  is  ready  for  immediate 
service. 

The  Conqueror  of  the  Phagocyte.  Nevertheless,  although 
a  young  and  healthy  phagocyte  may  be  so  vigorous  as 
to  be  like  a  Samson  among  his  microbe  enemies,  still,  as 
we  have  seen  already,  there  is  a  way  to  defeat  and  destroy 
him.  Let  one  of  these  young  phagocytes  be  launched 
into  blood  that  has  alcohol  in  it,  and  what  is  the  result  ? 
Does  he  gain  courage  for  the  fray?  Does  he  hurry  off 
to  the  battle  ground  with  the  greater  strength? 

Quite  the  contrary;  his  fate  is  now  sealed,  for  the 
alcohol  overcomes  him  with  a  subtle  power  more  deadly 
than  that  of  any  microbe.  It  is  a  poison  which  will  dull 
a  phagocyte  or  paralyze  him  utterly,  according  as  there 
is  more  or  less  of  it  in  the  blood. 

A  trace  of  alcohol  does  not  rob  phagocytes  of  all 
power.  They  may  still  be  strong  enough  to  reach  the 
scene  of  battle ;  they  may  even  contend  with  a  microbe 
on  the  way  there;  but  instead  of  being  strong  enough 
to  conquer,  they  are  now  weak  enough  to  be  conquered. 
When  such  a  condition  exists,  disease  microbes  find 


348        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

themselves   free   to    carry    on    their    business    of   toxin 
manufacture  without  interruption. 

From  beer  and  hard  cider  all  the  way  through  to  gin 
and  brandy,  every  drink  containing  alcohol  harms  the 
phagocyte,  and  the  more  alcohol  the  drink  holds  the 
more  is  the  phagocyte  damaged  by  it.  The  following 
table  shows  what  per  cent  of  alcohol  is  found  in  various 
drinks  that  are  in  common  use: 

PERCENTAGE  OF  ALCOHOL  IN   COMMON  DRINKS 

Beer 3-5 

Hard  cider 4-5 

Ale 7-8 

Wines  of  different  kinds 7-20 

Champagnes 11-18 

Brandy 30-55 

Whisky 50 

The  Man  who  Drinks.  In  view  of  this  power  of  alcohol, 
we  realize  that  when  a  man  raises  his  glass  cheerfully 
to  his  lips  and  drinks  to  the  health  of  his  king  or 
his  friend,  he  drinks  in  truth  to  the  success  of  disease 
microbes  in  his  own  body,  while  at  the  same  time  he 
drinks  to  the  death  of  his  own  most  faithful  bodyguard. 

If  the  owner  of  a  castle  had  drugged  his  watchmen 
on  the  towers,  had  bound  his  soldiers  hand  and  foot,  and 
had  killed  his  bodyguard,  would  he  have  the  right  to 
be  surprised  when  he  found  his  worst  enemy  within  the 
gates  ?  If  that  enemy  robbed  him,  or  beat  him  cruelly, 


MAN'S  FRIEND  AND  DEFENDER  349 

or  killed  him   by  slow  torture,   would  any  one  be  to 
blame  but  the  owner  of  the  castle  himself? 

Protect  your  phagocytes  from  harm  by  observing  the 
laws  of  health,  and  they  will  protect  you  in  time  of  need. 
Weaken  them  through  the  use  of  alcohol  or  any  other 
poison,  or  through  neglect  of  the  laws  of  health,  and 
you  will  be  as  a  man  who  has  drugged  his  watchmen 
on  the  towers,  bound  his  soldiers  hand  and  foot,  and 
killed  his  bodyguard.  He  who  has  done  all  this  is 
sure  to  suffer  when  the  enemy  comes. 

QUESTIONS 

1.  What    is    the    phagocyte?      2.  What    does    its    name    mean? 

3.  Describe  the  experiment  with  the  frog  and  the  cholera  microbes. 

4.  How  do  phagocytes  capture  and  destroy  microbes?    5.  Why  does 
a  frog  never  die  of  cholera  ?    6.  Why  do  pigeons  never  have  tuber- 
culosis ?    7.  Describe  the  action  of  phagocytes  in  the  body.    8.  If  in- 
truding disease  microbes  are  more  numerous  or  more  vigorous  than  our 
phagocytes,  what  happens  to  us  ?    9.   If  a  person  yields  quickly  to  a 
disease,  what  does  this  prove  about  his  phagocytes  ?     10.   If  he  is  able 
to  resist  disease,  what  is  it  that  has  saved  him?    11.  What  does  the 
phagocyte  do  in  case  we  are   cut  or  wounded?    12.   What  is   pus? 
13.  What  difference  may  there  be  in  the  healing  of  the  wounds  of 
two  men  in  a  hospital? 

14.  What  should  be  our  daily  command  about  phagocytes  ?  15.  What 
connection  is  there  between  the  laws  of  health  and  the  vigor  of  the 
phagocyte  ?  16.  What  was  noticed  during  the  cholera  epidemic  in  Glas- 
gow in  1848  ?  17.  How  do  you  explain  the  connection  between  the 
death  rate  and  the  drinking  of  alcohol?  18.  Tell  about  the  boy  and 
the  man  who  were  bitten  by  the  mad  dog.  19.  What  experiments  did 


350        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 

Dr.  Delearde  make  on  the  rabbits  ?  20.  How  did  he  explain  the 
results?  21.  Why  did  Bum  and  Tipsy  suffer  more  from  disease  than 
Nig  and  Topsy  ?  22.  Which  does  the  most  harm  in  the  body,  disease 
microbes  themselves  or  the  toxin  they  produce  ?  23.  In  a  case  of 
pneumonia,  why  'does  the  doctor  take  courage  when  phagocytes  in- 
crease their  numbers  ?  24.  Where  does  he  look  for  the  phagocytes  ? 
25.  What  occurs  when  a  phagocyte  finds  itself  in  blood  that  holds 
a  trace  of  alcohol?  26.  When  phagocytes  are  overcome  by  alcohol, 
what  is  the  outlook  for  disease  microbes  in  that  body?  27.  When  a 
man  drinks  to  the  health  of  his  friend,  to  whose  success  and  to  whose 
death  is  he  really  drinking  ?  28.  Why  should  we  protect  the  phagocytes 
from  harm  ? 


BIBLIOGRAPHICAL  LIST 

ALLEN,  W.  H.    Civics  and  Health. 

CANNON,  W.  B.    The  Movements  of  the  Stomach  studied  by  Means  of  the 

Rontgen  Rays.    American  Journal  of  Physiology,  Vol.  I. 
CANNON,  W.  B.    The  Movements  of  the  Intestines  studied  by  Means  of  the 

Rontgen  Rays.   American  Journal  of  Physiology,  Vol.  VI. 
CHITTENDEN,  R.  H.    The  Nutrition  of  Man.    1907. 
DE  FOREST,  ROBERT  W.,  and  VEILLER,  LAWRENCE.   The  Tenement  House 

Problem.    1903. 
GOLER,  GEORGE  W.    The  Influence  of  the  Municipal  Milk  Supply  upon  the 

Deaths  of  Young  Children.    1903. 

GULICK,  L.  H.    Physical  Education  by  Muscular  Exercise.    1904. 
GULICK,  L.  H.    The  Efficient  Life.    1907. 
HARVEY,  WILLIAM.    Anatomical  Disquisition  on  the  Motion  of  the  Heart 

and  Blood  in  Animals.    Written  in  1628.    Translated  from  the  Latin  by 

Robert  Willis. 
HORSLEY,  SIR  VICTOR,  and  STURGE,  MARY  D.    Alcohol  and  the  Human 

Body.    1907. 

HOUGH,  THEODORE,  and  SEDGWICK,  W.  T.  The  Human  Mechanism.   1906. 
HOWARD,  L.  O.    Mosquitoes:    How  they  Live;    How  they  Carry  Disease; 

How  they  are  Classified ;   How  they  may  be  Destroyed.    1902. 
HOWELL,  W.  H.    A  Text-Book  of  Physiology  for  Medical  Students  and  Physi- 
cians.   1907. 
JAMES,  WILLIAM.   The  Principles  of  Psychology.    1893.  (Chapters  on  Habit, 

Will,  Memory,  Attention.) 

JEWETT,  FRANCES  GULICK.   The  Next  Generation.    1914. 
JEWETT,  FRANCES  GULICK.   Town  and  City.    1906. 
JEWETT,  FRANCES  GULICK.    Control  of  Body  and  Mind.    1908. 
MCKEEVER,  WM.  A.    The  Cigarette  Smoking  Boy.    1 909. 
SARGENT,  DUDLEY  A.    Health,  Strength,  and  Power.    1904. 
SCHMIDT,  FERDINAND  AUGUST.    Unser  Korper.    1903. 
SEAVER,  J.  W.   Effects  of  Nicotine.    The  Arena,  Vol.  XVII. 
STILES,  C.  W.   Hookworm  Disease.    1910. 


GLOSSARY 


KEY  TO   PRONUNCIATION 

a  as  in  fate,  senate,  fat,  arm,  all,  ask,  what,  care. 

e     "  mete,  £vent,  met,  her,  there,  they. 

ee  "  feet. 

i     ff  Ice,  idea,  it,  sir,  machine. 

o     ff  old,  obey,  n5t,  move,  wolf,  son,  hCrse,  work. 

oo  ff  food,  foot. 

u    ff  use,  unite,  up,  fur,  rule,  pull. 

y    ff  fly,  myself,  baby,  myrrh. 

au  fr  author. 

aw fr  saw.  ew 

oy  ff  boy.  ou 

5 
5h 

g(=j) 
n(  =  ng) 
si  (=sh) 
th 
J(=gz) 


saw. 

boy. 

c    (unmarked)  as  in  call ; 
ch  (unmarked)     fr     child 
g   (unmarked)     "     go; 
ng        as  in  ring. 
§(  =  z)     "     is. 
th  (unmarked)  as  in  thin ; 
x   (unmarked)     ff     vex; 


as  in  new. 
"     out. 
"    mice. 
"     chaise  ; 
fr     cage. 

ink. 

tension 

then. 

exact. 


oi 

ow 


as  in  boil. 
"     cow. 


ci  (=sh) 


gracious, 
school. 


ph  (  =  f)    as  in  phantom, 
si    (=zh)     ft     vision, 
ti   (=sh)     ff     motion. 


Obscure  sounds :  a,  e,  i,  etc.    Silent  letters  are  italicized. 


Sb  do'mgn,  the  part  of  the  body 
below  the  diaphragm. 

ad'e  noid,  a  growth  of  tissue  in  the 
back  of  the  nose. 

a  dul'ter  ate,  to  make  impure. 

alimentary  canal,  the  food 
canal. 

an  oph'e  leg,  a  species  of  mos- 
quitoes that  carry  malaria. 

antlsgp'tlc,  anything  which  de- 
stroys the  microorganisms  of 
disease. 


an  ti  tox'in,  a  substance  which  neu- 
tralizes the  action  of  a  toxin  or 
poison. 

an'vil,  one  of  the  small  bones  of 
the  ear. 

a  or'ta,  the  great  artery  from  the 
heart. 

a'pgx,  the  top  or  summit  of  any- 
thing. 

a/que  ous  hu'mor,  the  liquid  be- 
tween the  crystalline  lens  and 
the  corona  of  the  eye. 


353 


354       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


ar'ehl  t6ct,onewho  plans  buildings. 

ar  te'rl  al,  pertaining  to  the  arteries. 

ar'ter  y,  one  of  the  vessels  or  tubes 
which  carry  the  blood  from  the 
heart. 

as  tig 'ma  tlgm,  a  defect  in  the  re- 
fractive apparatus  of  the  eye. 

afro  phy,  a  wasting  away  from  lack 
of  nourishment. 

au'dl  to  ry,  pertaining  to  the  outer 
and  inner  passages  of  the  ear. 

au'ri  cle,  a  division  of  the  heart  re- 
ceiving blood  from  the  body. 

au'to-In  tox  I  ca'tion,  poisoning  of 
the  body  by  toxins  formed  within 
the  body. 

ax 'on,  a  fiber  from  the  cell  body. 

ba  Qll'Zus,  a  microbe  which  is  the 

cause  of  various  diseases, 
bac  te'rl  a,  forms  of  microbes. 
beVer  age,  drink  of  any  kind. 
bl'Qgps,  a  muscle  having  two  heads ; 

the  term  is  applied  to  a  muscle 

in  the  arm. 
bile,  a  yellow,  bitter  fluid,  secreted 

by  the  liver. 

bis/muth  subnitrate,  a  chemical, 
bron'ehi  al,  belonging  to  the  tubes 

or  air  passages  of  the  lungs, 
bron'ehi  die,  a  small  bronchial  tube. 

caf/elne,  an  alkaloid  found  in 
coffee. 


la  ry,  one  of  the  tubes  con- 
necting arteries  and  veins, 
car 'bo  hy'drate,  a  chemical  term, 
car'bon  di  ox'ide,  carbonic  acid  ;  a 

gas. 

car'di  ac,  pertaining  to  the  heart, 
car'tl  lage,  an  elastic  tissue;  gristle. 
cel'Zu  lose,  the  inclosing  membrane 

of  plant  cells. 
q8r  e  b8l7um,  a  division  of  the  brain 

situated  at  the  back  of  the  head 

below  the  cerebrum. 
Qgr'e  brum,  the  upper  and  larger 

division  of  the  brain, 
ehol'er  a,  an  infectious  and  often 

fatal    disease   of    the    digestive 

organs, 
chyle,  the  contents  of  the  small 

intestine, 
chyme,  food  in  the  form  in  which 

it  passes  out  of  the  stomach, 
cjl'l  a,    minute     hairlike    growths 

from   a  cell   or   other   part   or 

organ  of  the  body. 
cjr  cu  la'tion,  motion  in  a  circle  or 

circuit. 

Qir'cu  la  to  ry,  pertaining  to  circu- 
lation, as  of  the  blood, 
co  ag  u  la'tion,  the  act  of  changing 

from  a  fluid  to  a  thickened  state, 
co'calne,  a  drug  which  produces 

local  insensibility, 
coeh'le  a,  a  part  of  the  inner  ear 

in  most  vertebrate  animals. 


GLOSSARY 


355 


con  'cave,  curved  in. 

con  trac'tion,  a  shrinking;  shorten- 

ing. 
cor'ne  a,  the  hard  transparent  front 

portion  of  the  eyeball. 
cor  'pus  cle,  a  minute  particle  ;  blood 

corpuscles  —  the  blood  disks  or 

cells. 
cor'tgx,  the  layer  of  gray  matter 

covering  the  surface  of  the  brain. 
crude,  raw,  not  fitted  for  use  by 

any  artificial  process. 
crys'tal  line  len§,  a  lens  of  high 

refracting  power  behind  the  iris 

of  the  eye. 
cu'lgx,  the  common,  harmless  mos- 

quito. 

cur'va  ture,  a  bend  ;  a  curve. 
<7zar'e  vftch,  the  title  applied  to  the 

eldest   son   of   the   emperor  of 

Russia. 

dgn'drlte,  a  crooked  fiber  from  the 

cell  body. 

der'mls,  the  second  layer  of  skin. 
dl'a  phra^m,  a  muscle  separating 

the  chest  from  the  abdomen. 
dlph  the'rl  a,  a  disease  of  the  throat. 
dls  In  fgc'tion,  destruction  of  the 

germs  of  contagious  diseases. 


a    disease    attacking 
many  persons  at  the  same  time. 
6p  I  der'mls,   the    outer    layer  of 
skin. 


6p  I  glottis,  a  valvelike  organ 
which  keeps  food  and  drink  from 
getting  into  the  larynx. 

e  rup'tlve  disease,  a  type  of  disease 
affecting  the  skin. 

8r  y  slp'e  las,  a  disease  character- 
ized by  an  inflammation  of  the 
skin  and  accompanied  by  fever. 

JHfr  sta'ehl  an  tube,  a  tube  leading 
from  the  middle  ear  to  the 
pharynx. 

8x  peVto  rate,  to  spit. 

Sx  tgn'sor,  a  muscle  which  extends 
or  straightens  any  part  of  the 
body. 

flgx'or,  a  muscle  which  bends  any 
part  of  the  body. 

gan'gll  on  (plural,  ganglia),  a  col- 
lection of  nerve  cells. 

gas 'trie  juice,  a  fluid  secreted  by 
the  stomach. 

gel 'a  tin,  a  substance  made  by  boil- 
ing bones  and  other  tissues. 

germ,  microbe. 

gland,  a  secretory  part  or  organ, 
which  secretes  a  substance  pecu- 
liar to  itself. 

glob'ule,  a  little  globe. 

glottis,  the  mouth  of  the  windpipe. 

gly'co  ge"n,  a  substance  found  in 
many  animal  tissues  and  espe- 
cially abundant  in  the  liver. 


356       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


goi'ter,  enlargement  of  the  thyroid 
gland  on  the  front  and  sides  of 
the  neck. 

grSn'ule,  a  little  grain,  a  fine  particle. 

gym'nast,  one  skilled  in  athletic 
exercises. 

ham'mer,  one  of  the  small  bones 

of  the  middle  ear,  named  from 

its  shape. 
hi'ber  nate,  to  pass  the  winter  in  a 

torpid  state,  as  some  animals  do. 
hy  dro  ehlo'iic  acid,  an  acid  formed 

by  the   union   of  chlorine  and 

hydrogen. 
hy  dro  pho'bl  a,  a  disease  caused 

by  the  bite  of  a  mad  dog. 

In  flu  Sn'za,  an  epidemic  catarrh. 
In  gred'i  ent,  one  of  the  elements 

of  a  combination,  as  a  drink  or 

medicine. 
In  oc'u  late,  to  introduce  germs  into 

the  tissues  for  protection. 
In  ter  cos'tal,  between  the  ribs. 
In  tgs'tme,  the  lower  part  of  the 

alimentary  canal. 
1'rls,  the  colored  curtain  of  the  eye, 

seen  in  the  front  of  the  eyeball. 


rinth,  part  of  the  inner  ear. 
l&eh'ry  mal  gland,  a  gland  which 

secretes  tears. 
laVynx,  the  part  of  the  windpipe 

in  which  vocal  sound  is  made. 


lat'er  al,  sidewise. 

league,  persons  united  for  some 
particular  purpose. 

Hg'a  ment,  the  tissue  that  connects 
bones. 

lymph,  a  colorless  fluid  found  in 
animal  bodies. 

lym  phat'Ic,  a  vessel  which  con- 
veys lymph. 

m£i'row,  a  soft  tissue  found  in  the 

interior  of  the  bones. 
me&'§le§,   an   eruptive  contagious 

disease, 
rngm'brane,  a  thin  soft  tissue  in 

the   form   of  a  sheet  or   layer 

covering  parts  of  the  body, 
meii'u,  a  bill  of  fare, 
mi'crobe,  a  creature  so  small  that 

it  can  be  seen  only  through  a 

microscope. 
Ml  cro  ne'sla,  a  collection  of  islands 

and   groups   of    islands   in   the 

Pacific  Ocean, 
mi'cro  scope,    an    instrument    for 

examining  objects  too  small  to 

be  seen  by  the  naked  eye. 
mu'cus,  a  thick  fluid  secreted  by 

the  mucous  membrane  of  ani- 
mals, 
mus'cle,  a  tissue  the  contraction  of 

which  causes  motion, 
mus'cular,  having  well-developed 

muscles;  strong. 


GLOSSARY 


357 


narc6t'Ic,  a  substance  having  the 
power  to  produce  stupor. 

neu'ron,  a  nerve  cell. 

nlc'6  tine,  a  highly  poisonous  sub- 
stance obtained  from  tobacco. 

nl  trog'e  nous,  pertaining  to  nitro- 
gen. 

nor'mal,  regular ;  natural. 

nu'cle  us,  the  vital  center  of  a  cell. 

nu  tri'tion,  that  which  nourishes 
or  repairs  the  waste  in  tissues. 

oesophagus  (e  sofa  gus),  the  tube 
through  which  food  and  drink 
are  carried  to  the  stomach. 

61  fac'to  ry  nerve,  the  nerve  con- 
nected with  the  sense  of  smell. 

6 'pi  urn,  the  dried  juice  of  the 
poppy;  a  drug. 

Sp'tlc  nerve,  the  nerve  connected 
with  the  sense  of  sight. 

or'gan'Ic,  pertaining  to  objects  that 
have  organs;  hence  pertaining 
to  the  animal  and  vegetable 
worlds. 

6s  mo 'sis,  the  diffusion  of  fluids 
through  animal  membranes. 

6x  I  da'tion,  the  process  of  com- 
bining with  oxygen. 

ox'ygen,  the  element  of  the  air 
that  supports  animal  life. 

pal 'ate,  the  roof  of  the  mouth  and 
floor  of  the  nose. 


pan 'ere  as,  a  gland  near  the 
stomach  which  secretes  a  fluid 
having  important  uses  in  diges- 
tion. 

pan  ere  at'Ic  fluid,  a  clear  liquid 
secreted  by  the  pancreas. 

par 'a  lyze,  to  render  helpless. 

Pas'teur  Institute,  a  place  where 
Pasteur's  method  of  treating 
certain  diseases  is  practiced. 

pat'ent  mgd'I  cine,  a  ready-made 
medicine,  sometimes  patented. 

per  I  6s 'te  um,  a  fibrous  membrane 
covering  the  surface  of  bones. 

per  I  stal'tlc,  contracting  in  suc- 
cessive circles. 

phag'6  cjte,  a  white  blood  corpuscle. 

phar'ynx,  the  part  of  the  food  canal 
between  the  mouth  and  the 
oesophagus. 

plg'ment,  coloring  matter. 

plas'ma,  the  liquid  part  of  the 
blood. 

pleu'ra,  the  membrane  which  lines 
the  walls  of  the  chest. 

pleu'risy,  inflammation  of  the 
pleura. 

plgx'us,  a  network  of  nerves. 

pneumo'nla,  inflammation  of  the 
tissues  of  the  lungs. 

Po'nape,  one  of  the  Caroline 
Islands. 

pro'te  Id,  a  substance  from  which 
living  tissue  is  formed. 


358       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


pro 'to  plasm,  a  substance  consti- 
tuting the  basis  of  life  of  all 
plants  and  animals. 

pto  ma'Ine,  a  substance  formed 
from  animal  or  vegetable  tissues 
during  putrefaction. 

pul'mo  n  a  ry,  pertaining  to  the 
lungs. 

pulse,  the  beating  of  the  heart  as 
felt  in  the  arteries. 

pus,  an  inflammatory  liquid  issuing 
from  abscesses  or  sores. 

py  lor'Ic,  pertaining  to  the  pylorus. 

py'lo'rus,  the  opening  through 
which  the  contents  of  the 
stomach  pass  into  the  intestine. 

r6g  I  mgn'tals,  military  clothing. 

r/iyth'mlc,  occurring  at  regular  in- 
tervals, like  accents  in  poetry  or 
music. 

rlck'ets,  a  disease  of  children,  in 
which  they  are  weak  in  the 
joints. 

ro'tate,  to  revolve  ;  to  move  round 
a  center. 

sal  I  Qyl'Ic,  the  name  of  an  acid. 

sa  li'va,  a  digestive  fluid  secreted  by 
glands  in  the  mouth. 

sal 'I  va  ry,  pertaining  to  saliva. 

san  I  ta'tion,  putting  and  keeping 
anything  in  healthy  condition. 

sar  co  iSrn'ma,  the  covering  of  sep- 
arate muscle  fibers. 


scle  rSt'Ic  coat,  part  of  the  eyeball. 

sew'age,  the  matter  which  passes 
through  sewers. 

skel'e  tal,  pertaining  to  a  skeleton. 

sphyg'mo  graph,  an  instrument 
used  in  determining  the  strength 
of  the  heart  beat. 

spu'tum,  that  which  is  spit  or  raised 
from  the  lungs. 

st8g  6  my 'I  a,  a  mosquito  that  car- 
ries yellow  fever. 

stlm'u  lant,    that  which  excites. 

stlr'rup,  one  of  the  three  bones  of 
the  middle  ear. 

stom'aeh,  part  of  the  digestive 
apparatus. 

sym  mgt'rlc  al,  well  proportioned 
in  its  parts. 

syno'vial  fluid,  secreted  in  the 
joints. 

syr'Inge,  an  instrument  like  a 
pump,  for  drawing  in  and  eject- 
ing liquids. 

sys  t8m'Ic,  pertaining  to  the  body 
as  a  whole. 

tad 'pole,  the  young  of  a  frog. 

tgn'don,  a  bundle  of  fibers  which 
joins  a  muscle  to  a  bone. 

tgnsely,  tightly ;  rigidly, 

the'Ine,  a  substance  found  in  tea. 

the  6  bro'mlne,  an  alkaloid  sub- 
stance found  in  chocolate  and 
in  cocoa. 


GLOSSARY 


359 


tiio  rac/ic,  pertaining  to  the  thorax, 

or  chest. 

thy'roid,  a  gland  in  the  neck, 
ton'sil,  one  of  two  oval  bodies  on 

each  side  of  the  opening  of  the 

throat. 
tox'In,  a  poison  produced  in  the 

body, 
tra'ehe  a,  the  windpipe,  beginning 

at  the  larynx  and  ending  at  the 

bronchial  tubes. 

tra  eho'ma,  a  disease  of  the  eyes, 
tu  ber  cle,  a  small  mass  of  diseased 

matter, 
tu  ber  cu  lo'sis,  a  disease  caused  by 

the  tubercle  bacillus, 
ty'phoid,  a  disease  caused  by  con- 
taminated food  or  drink, 
ty'phus,  a  kind  of  fever. 


vSc  QI  na'tion,  inoculation  with  vac- 
cine to  prevent  smallpox. 

va'por  Ize,  to  convert  a  liquid  into 
vapor. 

viein,  a  vessel  which  receives  blood 
from  the  capillaries  and  returns 
it  to  the  heart. 

ve'nous,  pertaining  to  the  veins. 

vgn'tri  cle,  a  division  of  the  heart 
receiving  blood  from  the  auricle. 

ver'te  bra,  one  of  the  small  bones 
which  make  up  the  spine. 

vi!7us  (plural,  vi!7i),  a  minute  ele- 
vation on  the  lining  of  the  small 
intestine. 

vit're  ous  hu'mor,  the  transparent 
jelly  which  fills  the  back  part  of 
the  eyeball. 

vol'a  til  Ize,  to  cause  to  evaporate. 


FOREIGN  NAMES 


Aschaffenburg  (a  sha/fen  boork) 

De  bove' 

De  le  arde' 

Fai  sans' 

Flourens  (floorans') 

No  tel  de  Ville'  ~ 


Krae'pe  I'm 


M6#ch'nl  koff 
Pavlov  (pav'lof) 
Treves 


INDEX 


Adams,  Dr.,  343 

Adenoids,  114 
treatment  for,  115 

Air,  need  that  it  be  fresh,  303-305 
need  of  moisture  in,  118 

Air  sac,  description  of,  117 
gas  exchanges  through,  no 
location  of,  109 
muscular  wall  of,  28 
when  inactive,  in,  112 

Alcohol,  curtailing  sale  of,  in  England, 

189 

effect  of,  on  the  heart,  97,  98,  100 
effect  of,  on  the  phagocyte,  345 
effect  of,  on  soldiers,  262 
effect  of,  on  taxes,  crime,  and  poverty, 

191,  192 

effect  of,  on  typesetters,  261,  262 
French  attitude  towards,  186 
German  attitude  towards,  187 
legislation  about,  in  Japan,  189 
movement    against,    in    the    United 

States,  189 

percentage  of,  in  common  drinks,  348 
prohibition  of,  in  Newfoundland,  191 
prohibition  of,  in  Russia,  188 
relation  of,  to  efficiency,  260-265 
relation  of,  to  heart  beat,  96 
relation  of,  to  hydrophobia,  344 

Alimentary  canal,  description  of,  146 

Anderson,  Dr.,  122 

Animals,  cold-blooded,  203 
warm-blooded,  203 

Anopheles,  a  mosquito,  329 

Antiseptics,  value  of,  335 

Anvil,  bone  in  the  ear,  249 

Arteries,  location  of,  58,  60 
what  they  are  for,  57,  58 

Aqueous  humor,  part  of  the  eye,  246 

Aschaffenburg,  Dr.,  261,  262 

Auditory  canal,  part  of  the  ear,  248 


Auricle,  61,  63 

Australians,  trained  sight  of,  239 

Auto-intoxication,  174 

prevention  of,  175,  176 
Axon,  part  of  the  neuron,  226 

Back,  reasons  for  its  shape,  13,  14 

Bacteria,  268 

Biceps,  exercise  for,  17 

tendons  of,  23 
Bile,  a  digestive  fluid,  155 

where  manufactured,  169 
Bismuth,  use  of  in  experiments,  141 
Blood,  in  the  arteries,  88 

carrier  of  oxygen,  105 

changed  while  in  the  lungs,  109 

examining  a  drop  of,  82 

exchange  of  gases  in,  87 

flow  of,  60 

individual  supply  of,  70 

under  the  microscope,  83 

in  the  veins,  89 

what  it  does,  85 
Body  cavities,  180 
Body  temperature,  207,  208 

regulation  of,  202 
Bones,  chemical  composition  of,  32 

in  the  ear,  249 

effect  of  work  on,  36 

of  the  foot,  40 

the  framework  of  the  body,  30-46 

how  held  together,  35 

number  of,  34 

records  of,  4 

shape  and  size  of,  33 

structure  of,  30 

tuberculosis  of,  296 

young  and  old,  33 
Brain,  aided  by  the  sympathetic  ganglia, 

253 
center  of  the  senses,  242 


361 


362        PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


Brain,   gray  and  white   substances  of, 
219,  220-231 

structure  of,  217 
Breathlessness,  avoidance  of,  107 

cause  of,  105,  106 

description  of,  103 
Bridgman,  Laura,  243 
Bronchial  tubes,  description  of,  117 
Bronchioles,  description  of,  117 
Brotherhood  of  Locomotive  Engineers, 
190 

Caffeine,  a  poison,  165 
Candy,  why  objectionable,  165 
Cannon,  Dr.,  138,  150,  255 
Capillaries,  connections  of,  64 

definition  of,  68 

in  the  liver,  171 

relation  of,  to  air  sacs,  no 

relation  of,  to  warmth,  98 
Carbohydrate,  definition  of,  124 

as  energy  producer,  127 
Carbon  dioxide,  effect  of,  on  the  color 
of  blood,  109 

exchange  of,  for  oxygen,  118 

in  the  lungs,  no 

when  produced,  105 
Cardiac  muscle,  location  of,  141 

office  of,  147 
Carpenter,  Dr.,  240 
Cartilage,  between  vertebrae,  35 

defined,  116  (footnote) 

in  young  bodies,  3 

Cats,  food  experiments  with,  138-144 
Cell  body,  part  of  neuron,  226 

as  telegraph  center,  228 
Cellulose,  an  envelope,  127 

softened  by  cooking,  163 
Cerebellum,  as  aid  to  the  cerebrum,  233 

location  of,  218 

training  of,  233-250 

work  of,  233 
Cerebrum,  appearance  of,  218 

centers  in,  220 

location  of,  217 

and  memory,  216 
China,  small  feet  in,  38,  39 
Chittenden,  Professor,  121,  131 
Chocolate  as  a  drink,  164 
Cholera  and- alcohol,  343,  344 


Choroid  coat  of  the  eye,  246 

Chyle,  relation  of,  to  the  villi,  151,  158 

where  found,  147,  149 
Chyme,  a  condition  of  food,  143 

preparation  of,  147 
Cigarettes,  effect  of,  on  heart,  80 
Cilia,  location  of,  117 
Circulation,  Harvey's  discovery  of,  64 

when  slow,  95 

Circulatory  system,  description  of,  65 
Clothes,  why  needed,  204 
Coagulation,  description  of,  83 
Cochlea,  part  of  the  ear,  249 
Cocoa,  objectionable  feature  of,  164 
Coffee,  why  harmful,  165 
Cold,  how  to  check  a,  201 

rules  of  prevention  for  a,  201,  202 

symptoms  of  a,  200 

taking,  199 

Colon,  location  of,  148 
Connective  tissue,  22 
Consumption  not  heritable,  297 
Cornea,  description  of,  246 
Corpuscles,  in  capillaries,  67 

description  of  red,  84 

description  of  white,  85 
Cortex,  cell  bodies  in,  227 

how  developed,  244 

of  Laura  Bridgman's  brain,  244 

name  of  gray  layer,  221 
Crystalline  lens,  part  of  the  eye,  246 
Culex,  a  mosquito,  329 
Curvature  of  spine,  9 

prevention  of,  10 

Debove,  Professor,  186 
Delearde,  Dr.,  345 
Dendrite,  part  of  neuron,  226 
Dermis,  location  of,  197 
Diaphragm,  location  of,  182,  183 

rhythmic  movement  of,  183 
Digestion,  chemical  fluids  of,  154-156 

emotions  which  aid,  144 

emotions  which  hinder,  143 

and  good  temper,  255 

influenced  by  appetite,  162 

of  milk,  1 60 

process  of,  138-152 

Diphtheria,  cause  and  prevention  of, 
326 


INDEX 


363 


Disinfection,  importance  of,  335 
Donovan,  "  Mike,"  81 
Dyes,  danger  from,  285 

Ear,  hygiene  of,  249 

structure  of,  248,  249 
Eardrum,  part  of  the  ear,  248 
Eating,  mistakes  in,  158 

rules  for,  130 

Edwards,  Mr.,  football  captain,  80 
Epidermis,  value  of,  197 
Epiglottis,  115 

Eustachian  tube,  location  of,  249 
Excretion,  organs  of,  183 
Exercise,  advantage  of,  to  lymph  flow, 
92 

effect  of,  on  blood  supply,  71 

value  of,  to  health,  112 

warmth  by  means  of,  205 

when  to  be  avoided,  145 
Eyes,  diseases  of,  270,  271 

protection  of,  270,  271 

structure  of,  245,  246 

Facial  expression  controlled  by  neurons, 

237 

Faisans,  Dr.,  186 
Fat,  reduction  of,  206 

stored  in  the  body,  127 
Fatigue,  effect  of,  on  nerve  cells,  230 

remedy  for,  230 
Fisher,  Professor,  305 
Flies,  what  they  eat,  273 

why  objectionable,  271 
Flourens,  Dr.,  233 
Food,  for  bulk,  need  of,  132 

canned,  286 

five  substances  of,  124 

as  fuel,  205 

inspection  of,  285 

laws  for  protection  of,  285 

production  of,  by  plants,  126 

study  of  cost  of,  126 

waste,  152 

what  it  does  for  the  body,  123 

why  we  cook  it,  163 
Food  tube  and  peristaltic  action,  148, 

149,  150 
Foot,  arch  of,  41 

deformed  by  shoes,  41 


Foot,  rules  of  hygiene  for,  42 
under  pressure,  38,  39 

Gall  bladder,  169 
Ganglia,  cell  bodies  in,  227 

definition  of,  227 

influenced  by  happiness,  256 

location  of,  254 

service  from,  258 
Gastric   glands,   location   and   use   of. 

147.  !5S 

Gastric  juice,  155,  161 
Gelatin  from  bone,  32,  33 
Germs,  meaning  of,  268 
Glands,  177 

ductless,  177 

lachrymal,  177 

thyroid,  177 

Glottis,  description  of,  115 
Glycogen,  168 

manufacture  of,  interfered  with,  178 

Hammer,  bone  of  the  ear,  249 
Happiness,  and  good  digestion,  144 

why  helpful,  256 
Harvey,  Dr.,  his  discovery,  56 
Headache,  relation  of,  to  auto-intoxica- 
tion, 176 
Health  and  Safety,  references  to,  109, 

113,  117,  118,  130,  135,  164,  345 
Heart,  action  of,  influenced  by  happi- 
ness, 256 

development  of,  56 

effect  of  exercise  on,  50 

how  weakened,  101 

muscles  of,  52 

overstretching,  54 

overtaxing,  52 

size  of,  55 

structure  of,  62 

training,  53,  54 

work  of,  58 
Heart  beat  tested,  50 
Heidelberg  University,  260 
Hodge,  Dr.,  230 
Hookworm  disease,  329-332 
Howell,  Dr.,  216 

Hydrochloric  acid  in  the  stomach,  155 
Hydrophobia,  and  alcohol,  344 

cause  and  prevention  of,  327 


364       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


Indians,  flat  heads  secured  by,  4 
Intestinal  juice,  digestive  fluid,  156 
Iris,  part  of  the  eye,  246 

Jenner,  Dr.,  325 

Joints,  ball-and-socket,  44 

hinge,  43 

their  location,  42,  43 

Kidneys,  172 

effects  of  alcohol  on,  173 

relation  on,  of  proteid,  129 
Koch,  Dr.  Robert,  289 
Kraepelin,  Professor,  260 

Labyrinth,  part  of  the  ear,  249 

Lachrymal  gland,  245 

Lacing,  harm  of,  178 

Large  intestine,  description  of,  148 

Larynx,  description  of,  116 

Lieutenant  Rengt  Boy,  262 

Ligaments  in  foot  and  ankle,  40 

illustration  of,  38 
Liver,  effects  of  alcohol  on,  170 

effects  of  lacing  on,  178 

what  it  is  and  what  it  does,  168-171 
London,  overcrowding  in,  282 
Lord,  Dr.,  273 

"  Lung  Block,"  death  rate  in,  292 
Lungs,  action  of,  influenced  by  happi- 
ness, 256 

clean  air  for,  117 

effect  of  lacing  on,  180 

expansion  of,  108 

relation  of,  to  blood,  109 

structure  of,  108 

trained  and  untrained,  108 

work  of,  109 
Lymph,  composition  of,  89 

description  of,  91 

Lymphatic  system,  description  of,  89-93 
Lymphatics  in  the  hand,  91 

McBride,  Mr.,  80 

McKeever,  Dr.,  73 

Malaria,  cause  and  prevention  of,  328, 

329 

Marrow,  34 

Marshall  Field  and  Company,  190 

Mayer,  Dr.;  9 


Measles,  cause  and  prevention  of,  323, 

324 
Memory,  as  related  to  the  cerebrum, 

216,  217 

Menus,  balanced,  131,  133 
Mernetsch,  Dr.,  264 
Metchnikoff,  Professor,  338,  339,  340, 

344 

Microbes,  danger  of,  from  public  towel, 
248 

deaths  caused  by,  in  war,  272 

definition  of,  268 

effect  of  cooking  on,  164 

how  they  attack  us,  269 

of  influenza,  341 

in  the  intestine,  174,  175 

menace  of,  267-277 

and  the  phagocyte,  338 

and  the  public  drinking  cup,  267 

safety  from,  322-336 

on  sand  filters,  312  (footnote) 

of  typhoid  fever,  309 

typhoid,  in  milk,  316 

the  way  they  damage  teeth,  134 

when  we  take  cold,  200 
Milk,  causes  of  impurity  of,  319 

conditions  of  cleanliness,  317 

conditions  of  uncleanliness,  318 

how  made  safe,  319 

and  microbes,  316 
Mineral  food,  where  found,  129 
Mosquitoes,  relation  of,  to  disease,  328, 

329 

Mouth,  description  of,  146 
Mumps,  333 
Muscles,  antagonistic,  18 

in  bent  back,  13 

developed  without  apparatus,  19 

development  of,  17 

effect  of  work  on,  14,  15 

of  the  eye,  245 

fibers. of,  21,  24 

flexor  and  extensor,  18,  19 

how  shaped,  17 

to  increase  size  of,  20 

intercostal,  29 

involuntary,  28 

the    law   of    their    contracting    and 
stretching,  16 

records  made  by,  4 


INDEX 


365 


Muscles,  shapes  of,  21 
skeletal,  26 
structure  of,  20,  21 
toughness  of,  25,  26 
voluntary,  26 
weight  of,  28 

Narcotic,  definition  of,  98  (footnote) 
Nasal  duct,  245 

Nerve  fibers,  affected  by  spinal  curves, 
10 

appearance  of,  212,  213 

bundles  of,  222,  223 

different  sets  of,  213 

endings  of,  222 

from  ganglia,  254 

length  of,  214 
Nerves,  212 

when  cut  across,  224 

distribution  of,  215 

kinds  of  messages  carried  by,  224 

machinery  of,  221 
Nervous    system    under   command   of 

the  cerebrum,  233 
Neurons,  and  alcohol,  265 

in  the  cerebellum,  234 

and  facial  expression,  237 

four  facts  about,  238 

how  to  train  them,  235 

results  of  training,  236 

structure  of,  225-227 
Nicotine,  effect  of,  on  the  heart,  78 

how  it  gets  to  the  heart,  78 

and  the  sphygmograph,  73 
Nucleus  of  cell  body,  226 

(Esophagus,  description  of,  146 

Olfactory  nerve,  250 

Optic  nerve,  endings  of,  on  the  retina, 
246 

Osmosis,  law  of,  87 

Oxygen,  demand  of  fibers  for,  105 
part  of  the  air,  118 
relation  of,  in  the  blood,  no 

Palate,  location  of,  1 14 
Pancreatic  fluid  for  digestion,  156 
Parks  and  playgrounds,  283 
Pasteur  Institute,  338 
Patent  medicine,  objections  to,  287 
Pavlov,  Professor,  159,  162 


Pepsin,  155 

Periosteum,  definition  of,  30 

Peristaltic  action,  importance  of,  148 

object  of,  157 
Perspiration,  197,  199 

cooling  device,  205 

insensible,  199 

manufacture  of,  196 

sensible,  199 
Phagocyte,  and  alcohol,  345 

the  conqueror  of,  347 

description  of,  338 

man's  defender,  338 

method  of  work,  339 

and  pneumonia,  346 

as  scavenger,  342 
Pink  eye,  contagion  of,  335 
Pittsburgh,  former  conditions  in,  308 

change  in  its  death  rate,  311 
Plasma,  part  of  the  blood,  84,  91 
Pleura,  definition  of,  117 
Pleurisy,  117 
Plexus,  definition  of,  254 
Pneumonia,  and  the  phagocyte,  346 

prevalence  and  prevention  of,  334 
Poole,  Mr.  Ernest,  293 
Proteid,  124 

digestion  of,  161 

use  of,  129 

where  found,  128 
Pulse,  action  of,  48,  49 

relation  of,  to  heart  beat,  49 
Pupil,  part  of  the  eye,  246 
Pure-food  laws  in  the  United  States,  285 
Pus,  343 

Pylorus,  behavior  of,  during  digestion, 
140 

service  of,  to  the  stomach,  147 

work  of,  141,  142 

Rear  tenements  and  the  death  rate,  282 

Rennin  in  digestion,  155 

Retina,  part  of  the  eye,  246 

Riis,  Mr.,  323 

Rochester  and  clean  milk,  320 

Safety  through  carefulness,  274,  275 
Saliva,  effect  of,  on  carbohydrate,  160 

flow  of,  through  desire,  159 

what  it  does,  154 


366       PHYSIOLOGY,  HYGIENE,  AND  SANITATION 


Salivary  glands,  affected  by  chewing,  160 

number  of,  159 

Sand  filters,  safety  by  use  of,  311 
Sanitation,  in  city  surroundings,  277 

contrasts  in  country  and  city,  279 

conditions  of,  in  country,  277 

meaning  of,  278,  279 
Sarcolemma,  22 
Scarlet  fever,  cause  and  prevention  of, 

323 

Schmidt,  Dr.,  9 
Sclerotic  coat,  246 
Seaver,  Dr.,  79 
Secretion,  defined,  184 

from  glands,  162,  177 
Sensations,  significance  of,  211 
Sense  centers,  enlargement  of,  243 
Senses,  machinery  of,  242 

their  training,  238,  239 
Sepala,  Professor  Helenius,  188 
Sewage,   disposal   of,   in   country  and 

city,  279 

Sewage  system,  study  of,  284,  285 
Skin,  effect  of  heat  on,  195,  196 

structure  of,  197 

what  it  does,  198,  199 
Skull,  protection  for  the  cortex,  221 
Small  intestine,  147 

effect  of  lacing  on,  179 
Smallpox,  324 

vaccination  for,  325 
Smell,  sense  of,  250 
Smoking,  effect  of,  on  heart,  75,  76 

general  effects  of,  74 
Soldiers,  experiments  with  alcohol,  262 

in  eating  experiments,  121,  122 
Sparrow,  effect  of  fatigue  on  brain  cells 

of,  230 

Sphygmograph,  use  of,  to  show  heart 
beat  after  alcohol,  97 

description  of,  73 

records  made  by,  76,  77 
Spine,  9,  34,  35 

Spinal  cord,  cell  bodies  in,  227 
Spinal  nerves,  relation  of,  to  backbone, 

222 

Spine,  when  twisted,  8 

Sputum,  air  contaminated  by,  299,  300 

danger  from,  296 

disposal. of,  302 


Stagg,  Mr.,  80 
Starch.    See  Carbohydrate 
Stegomyia,  a  mosquito,  328 
Stimulant,  defined,  98  (footnote) 
Stimuli,  carried  by  nerves,  212,  214 

relation  of,  to  sense  apparatus,  244 
Stirrup,  bone  in  the  ear,  249 
Stomach,  action  of,  during  digestion, 

*39 

effect  of  lacing  on,  179 
influenced  by  happiness,  256 
relation  of,  to  alimentary  canal,  147 

Sweat  glands,  a  cooling  device,  206 
numbers  of,  196 
as  protectors,  195,  196 

Sympathetic    ganglia,    work    of,    252, 

253 

Sympathetic  nervous  system,  253,  254 
Synovial  fluid,  use  of,  46 

Tadpole,  corpuscles  in  tail  of,  67 
Tea,  why  harmful,  165 
Teeth,  care  of,  135 

how  damaged,  134 
Tendon,  description  of,  23,  24 

use  of,  46 

Theine,  a  poison,  165 
Theobromine,  a  poison,  165 
Tobacco,  effects  of,  73-81 
Tobacco  heart,  78 
Tonsils,  work  of,  114 
Touch,  sense  of,  250 
Trachea,  description  of,  117 
Trachoma,  relation  of,  to  public  towel, 

335 

Treves,  Sir  Frederick,  101 
Tubercle  bacillus,  description  of,  290- 
291 

how  distributed  and  lodged,  294,  295 

our  foe,  289 

in  the  lungs,  295 
Tuberculosis,  of  the  bones,  296 

death  rate  from,  289,  292,  293 

discovery  of  its  cause,  290 

not  found  among  pigeons,  340 

fresh  air  in  treatment  of,  303-305 

rules  for  its  prevention,  301,  302 

treatment  of,  301 

war  against,  297-299 
Tuberculosis  "  D's,"  five,  302 


INDEX 


367 


Typesetters,  tests  made  with,  261,  262 
Typhoid  microbes,  in  drinking-water, 

309 
in  milk,  316 

Vegetarians,  belief  of,  132 
Veins,  location  of,  58 

valves  in,  59 

work  of,  61,  63 
Vertebrae,  relation  of,  to  spinal  nerves, 

222 

wedge-shaped,  36 

what  they  form,  35 
Villi,  description  of,  148 

their  number  and  structure,  156 

what  they  are,  1 57 

what  they  do,  151 
Vitreous  humor,  part  of  the  eye,  246 


Vocal  cords,  location  of,  116 
treatment  of,  116 

Water,  the  body's  need  of,  130,  131 
how  purified,  311,  312 
from  lakes  and  wells,  313,  314 
the  London  supply  of,  315 
sources  of,  for  city  supply,  315 
when  contaminated,  308,  309 

Whooping  cough,  how  to  prevent  its 
spreading,  333 

X  ray,  showing  action  of  stomach,  143, 

144 

for   the    study    of   digestive    action, 
139 

Yellow  fever,  328,  329 


A.  LIBRARY 


YC  88359 


355356 

36 


UNIVERSITY  OF 'CALIFORNIA  LIBRARY 


